How to make PHP page for cancle order from custumer side in opencart 3.0

See more:

PHP

MySQL

MVC

e-commerce

Hi,
OpenCart 3.0 does not support order cancellation from customer side so
I am trying to make one php page for canceling order by customer side
i just add one button on order info page for order cancellation and I am just trying to update order_status_id so it will be show me accordingly
I am trying this code without modifying core file of OpenCart 3.0
But my code is not working

What I have tried:

<pre><?php
include 'config.php';
// Create connection
$conn = new mysqli(DB_HOSTNAME,DB_USERNAME,DB_PASSWORD,DB_DATABASE);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";

$sql = "UPDATE order SET order_status_id =8 WHERE customer_id= 2 ";

if ($conn->query($sql) === TRUE) {
    echo "Record updated successfully";
} else {
    echo "Error updating record: " . $conn->error;
}

$conn->close();

?>

<script>alert("The order was canceled!");
window.location.replace('/')
</script>

it show error

Error updating record: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'order SET order_status_id =8 WHERE customer_id= 2' at line 1 

If anybody is expert in OpenCart 3.0 MVC Programming then plz help me

Thanks