ProxyPanel/app/Http/Middleware/VerifyCsrfToken.php

<?php

namespace App\Http\Middleware;

use Illuminate\Foundation\Http\Middleware\VerifyCsrfToken as Middleware;

class VerifyCsrfToken extends Middleware {
	/**
	 * The URIs that should be excluded from CSRF verification.
	 *
	 * @var array
	 */
	protected $except = [
		"callback/notify"
	];
}