Quick Billing api

Billing_api.php

    public function passdata(){
         $users = User::all();
         foreach ($users as $key => $data) {
            // $data = ["Id", 'username', 'mobile_number','amount_to_bill']
             $this->Bill($data, $key);//The Bill function is called on every user data in the database.
         }
    }


    public function Bill($data, $key){
        $ch = curl_init( $url ); //The URL variable is the billing API endpoint
        # Setup request to send json via POST.
        $payload = json_encode( array( "customer"=> $data ) );
        curl_setopt( $ch, CURLOPT_POSTFIELDS, $payload );
        curl_setopt( $ch, CURLOPT_HTTPHEADER, array('Content-Type:application/json'));
        # Return response instead of printing.
        curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
        # Send request.
        $result = curl_exec($ch);
        curl_multi_add_handle($mh, $ch[$key]);
        // execute all queries simultaneously, and continue when all are complete
          $running = null;
          do {
            curl_multi_exec($mh, $running);
          } while ($running);
        // curl_close($ch);
        // # Print response.
        echo "<pre>$result</pre>";//Here we expect a 200(Ok) or 500(if error)
    }