How to fix fs#writefile?

PS C:\Users\name\Desktop\DiscBot\AAA My Custom Discord Bot> node .
Nice.
(node:6444) UnhandledPromiseRejectionWarning: Error: Incorrect login details were provided.
    at WebSocketConnection.client.ws.connection.once.event (C:\Users\name\Desktop\DiscBot\AAA My Custom Discord Bot\node_modules\discord.js\src\client\ClientManager.js:48:41)
    at Object.onceWrapper (events.js:286:20)
    at WebSocketConnection.emit (events.js:198:13)
    at WebSocketConnection.onClose (C:\Users\name\Desktop\DiscBot\AAA My Custom Discord Bot\node_modules\discord.js\src\client\websocket\WebSocketConnection.js:390:10)
    at WebSocket.onClose (C:\Users\name\Desktop\DiscBot\AAA My Custom Discord Bot\node_modules\ws\lib\event-target.js:124:16)
    at WebSocket.emit (events.js:198:13)
    at WebSocket.emitClose (C:\Users\name\Desktop\DiscBot\AAA My Custom Discord Bot\node_modules\ws\lib\websocket.js:191:10)
    at TLSSocket.socketOnClose (C:\Users\name\Desktop\DiscBot\AAA My Custom Discord Bot\node_modules\ws\lib\websocket.js:850:15)
    at TLSSocket.emit (events.js:203:15)
    at _handle.close (net.js:606:12)
(node:6444) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 2)
(node:6444) [DEP0018] DeprecationWarning: Unhandled promise rejections are deprecated. In the future, promise rejections that are not handled will terminate the Node.js process with a non-zero exit code.

var fs = require('fs');
const Discord = require('discord.js');
const bot = new Discord.Client();

const token = 'NTk5NTIyMzY4MDQ5NjQzNTUw.XSmgXw.mK2EyTJzGGB1MdT3JCmQkRW6oP4';

const PREFIX = "$";

bot.on('ready', () =>{
    console.log('I am online!');
    bot.user.setActivity("Test | Prefix: $")
})

bot.on('message', message=>{

    let args = message.content.substring(PREFIX.length).split(" ");

    switch(args[0]){
        case 'help':
            message.channel.sendMessage('$cyka | Gives back a good word.');
            message.channel.sendMessage('$rules | TrustedBusiness Rules.');
            message.channel.sendMessage('$ping | Gives back the word [pong].');
        break;
        case 'cyka':
            message.channel.sendMessage('blyat!');
        break;
        case 'rules':
            message.channel.sendMessage('Check here and follow them please! #rules');
        break;
        case 'ping':
            message.channel.sendMessage('pong! POOOOONG!!');
        break;
        case 'clear':
            if(!args[1]) return message.reply('Sorry. Define also a number after (clear) command!')
            message.channel.bulkDelete(args[1]);
            break;
    }
})

bot.login(token)

var read_string = fs.readFile('number.txt', 'utf8', function (err, data) {
    if (err)
    return console.error(err);

    console.log('Nice.')
})