Comments by David Crow (Top 200 by date)

public void SendSMS()
{
    String[] sPermissions = { Manifest.permission.SEND_SMS,
                              Manifest.permission.READ_PHONE_STATE };

    if (! hasPermissions(sPermissions))
        androidx.core.app.ActivityCompat.requestPermissions(this, sPermissions, 1);
}

public boolean hasPermissions( String... sPermissions )
{
    for (String sPermission : sPermissions)
    {
        if (checkSelfPermission(sPermission) != PackageManager.PERMISSION_GRANTED)
            return false;
    }

    return true;
}

public void onRequestPermissionsResult( int requestCode, @androidx.annotation.NonNull String[] permissions, @androidx.annotation.NonNull int[] grantResults )
{
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (requestCode == 1)
    {
        if (grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED)
            Toast.makeText(this, "Permissions OK to now send message", Toast.LENGTH_SHORT).show();
        else
            Toast.makeText(this, "You don't have required permission(s) to send a message", Toast.LENGTH_SHORT).show();
    }
}

if (requestCode == REQUEST_SEND_PHONE_SMS)
{
    if (grantResults[0] == PackageManager.PERMISSION_GRANTED) 
    {
        if (requestCode == REQUEST_READ_PHONE_STATE) 
        {
...

var resultList = JsonConvert.DeserializeObject<Package[]>(json);
string lname = resultList.lastname;

ItemInfo itemInfo = list.remove(0);
list.add(itemInfo);
adapter.notifyDataSetChanged();

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <ImageView android:id="@+id/image"
        android:scaleType="centerCrop"
        android:layout_gravity="center"
        android:layout_width="50dp"
        android:layout_height="50dp" />

    <TextView android:id="@+id/tvText"
        android:textSize="20sp"
        android:textColor="@android:color/holo_blue_dark"
        android:textStyle="bold"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</LinearLayout>

public RemoteMessage.Notification getNotification ()
Gets the notification data from the message if set.

This field will be non-null if a notification message is received while the application is in the foreground.

Returns
The message notification or null.

getFirebaseMessage(remoteMessage.getNotification().getTitle(),remoteMessage.getNotification().getBody());

String sIcon = "i" + details.m_nIcon;
int nIcon = activity.getResources().getIdentifier(sIcon, "drawable", activity.getPackageName());
holder.mImage.setImageBitmap(BitmapFactory.decodeResource(activity.getResources(), nIcon));

import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;

import androidx.appcompat.app.AppCompatActivity;

public class HomeActivity extends AppCompatActivity
{
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.home_activity);

        ImageView Search = findViewById(R.id.imageView4);

        Search.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View v)
            {
                MediaPlayer player = MediaPlayer.create(HomeActivity.this, R.raw.search);
                player.start();
            }
        });
    }
}

Date dt(1620792785);
String s;
s.format("%02d:%02d", dt.getHour(), dt.getMinute());

startActivity(new Intent(SplashScreenActivity.this, MainActivity.class));
finish();

StringBuilder sb = new StringBuilder();

try
{
    URL url = new URL("https://api.openweathermap.org/data/2.5/weather?zip=74103&appid=1ebf50976c7bdea4db9a208956569a84&units=metric");
    HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
    if (connection.getResponseCode() == HttpsURLConnection.HTTP_OK)
    {
        String strLine;

        BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        while ((strLine = reader.readLine()) != null)
            sb.append(strLine);

        reader.close();
        connection.disconnect();

        JSONObject object = new JSONObject(sb.toString());

        JSONObject coords = object.getJSONObject("coord");
        double latitude = coords.getDouble("lat");
        Log.d("Test2", "latitude = " + latitude);
        double longitude = coords.getDouble("lon");
        Log.d("Test2", "longitude = " + longitude);

        JSONObject main = object.getJSONObject("main");
        double temp = main.getDouble("temp");
        Log.d("Test2", "temp = " + temp);
        double feels_like = main.getDouble("feels_like");
        Log.d("Test2", "feels_like = " + feels_like);
        int humidity = main.getInt("humidity");
        Log.d("Test2", "humidity = " + humidity);

        JSONObject wind = object.getJSONObject("wind");
        double speed = wind.getDouble("speed");
        Log.d("Test2", "wind speed = " + speed);
        int dir = wind.getInt("deg");
        Log.d("Test2", "wind from = " + dir);
    }
}
catch(Exception e)
{
    Log.e("Test2", e.getMessage());
}

Glide.with(this).load(url).into(memeImageView);

compile 'com.github.bumptech.glide:glide:3.7.0'

@Override
public void onClick(View v) 
{
    String username = userview.getEditText().getText().toString();
    Cursor c = sqLiteDatabaseObj.rawQuery("SELECT username FROM LOGINUSER WHERE username = ?", new String[] {username});
    if (c.getCount() == 0)
    {
        SQLiteDataBaseBuild();
        SQLiteTableBuild();

        String password = passview.getEditText().getText().toString();

        ContentValues cv = new ContentValues();
        cv.put(sqLiteHelper.KEY_User, username);
        cv.put(sqLiteHelper.KEY_PASS, password);

        try 
        {
            sqLiteDatabaseObj.beginTransaction();
            sqLiteDatabaseObj.insert(sqLiteHelper.TABLE_NAME, null, cv);
            sqLiteDatabaseObj.setTransactionSuccessful();
            sqLiteDatabaseObj.endTransaction();
            sqLiteDatabaseObj.close();
        } 
        catch (SQLException e) 
        {
            android.util.Log.e(TAG, e.getMessage());
        }              
    }
    else
    {
        Toast.makeText(MainActivity.this, "User Login Successfully", Toast.LENGTH_LONG).show();
        Intent intent = new Intent(MainActivity.this, Galaxy_Main.class);
        startActivity(intent);
    }
}

String username = userview.getEditText().getText().toString();
String password = passview.getEditText().getText().toString();

if (username.equals("admin") && password.equals("admin"))
{
    // SQLite query to insert data into table.
    ContentValues cv = new ContentValues();
    cv.put(sqLiteHelper.KEY_User, username);
    cv.put(sqLiteHelper.KEY_PASS, password);

    try
    {
        // Executing query.
        sqLiteDatabaseObj.beginTransaction();
        sqLiteDatabaseObj.insert(sqLiteHelper.TABLE_NAME, null, cv);
        sqLiteDatabaseObj.setTransactionSuccessful();
        sqLiteDatabaseObj.endTransaction();

        // Closing SQLite database object.
        sqLiteDatabaseObj.close();
    }
    catch(SQLException e)
    {
        android.util.Log.e(TAG, e.getMessage());
    }
}

So it looks as if you've shown us everything that is shown here:

https://answers.chartboost.com/en-us/child_article/android-integration

How is that helpful?  Unless you put those code snippets into their appropriate place in your project, I suspect it will not work.  You've not shown that.

"...but the SDK is still not initialized"

How are you verifying this?

JSONArray array = obj.getJSONArray("");
JSONObject data = array.getJSONObject(last_index);

if (1 <= sum3) {
            if ("4".equalsIgnoreCase(txt_alpha.getText().toString()) ||
                    ("5".equalsIgnoreCase(txt_alpha.getText().toString()) ||
                            ("6".equalsIgnoreCase(txt_alpha.getText().toString()) ||
                                    ("7".equalsIgnoreCase(txt_alpha.getText().toString()) ||
                                            ("8".equalsIgnoreCase(txt_alpha.getText().toString()) ||
                                                    ("9".equalsIgnoreCase(txt_alpha.getText().toString()) ||
                                                            ("10".equalsIgnoreCase(txt_alpha.getText().toString())))))))) {
                showNotif();
            }
        }

if (1 <= sum3) 
{
    int alpha = Integer.parseInt(txt_alpha.getText().toString());
    if (4 <= alpha && alpha <= 10)
        showNotif();
}

FileOutputStream fos = new FileOutputStream ("C:\\Users\\ICT-PROGRAMER\\Pictures\\" + gambar + ".jpeg");

DatabaseOpenHelper databaseOpenHelper = new DatabaseOpenHelper(this);
SQLiteDatabase db = databaseOpenHelper.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put("CustNum", m_customerInfo.m_nCustNum);
Calendar calNow = Calendar.getInstance();
cv.put("OrderDate", (double) calNow.getTimeInMillis() / 1000.0);
cv.put("Status", OrderInfo.STATUS_NEW);
long lOrderNum = db.insert("Orders", null, cv);
Log.d("Test", "Added order " + lOrderNum);

@Override
public void onBindViewHolder(ViewHolder holder, int position)
{
    ...
    holder.itemView.setTag(array.get(position));
    holder.itemView.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick( View view )
        {
            ItemDetails details = (ItemDetails) view.getTag();
            ...
        }
    });
}

public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent)
{
    if (convertView == null)
    {
        LayoutInflater vi = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = vi.inflate(resource_id_of_row, parent, false);
    }

    int nColor = Color.Green;

    // conditions that could change color go here

    convertView.setBackgroundColor(nColor);

    return convertView;
}