(add remaining validation rules/tests)

app/Http/Controllers/ConcertOrdersController.php

@@ -18,7 +18,9 @@ class ConcertOrdersController extends Controller
     public function store($concertId)
     {
         $this->validate(request(), [
-            'email' => 'required',
+            'email' => ['required', 'email'],
+            'ticket_quantity' => ['required', 'integer', 'min:1'],
+            'payment_token' => ['required'],
         ]);
 
         $concert = Concert::find($concertId);