Fatal error: Uncaught Error: Interface 'Illuminate\Contracts\Mail\Mailable' not found in D:\xampp\htdocs\psp\backend\vendor\laravel\framework\src\Illuminate\Mail\Mailable.php:22 Stack trace: #0 {main} thrown in D:\xampp\htdocs\psp\backend\vendor\laravel\framework\src\Illuminate\Mail\Mailable.php on line 22