Update UserController.php

app/Http/Controllers/Api/UserController.php

@@ -78,7 +78,11 @@ class UserController extends Controller
         $request->validate([
             "credits"      => "required|numeric|min:0|max:1000000",
         ]);
-
+        
+        if ($request->user()->credits + $request->credits >= 99999999) throw ValidationException::withMessages([
+            'code' => "You can't add this amount of credits because you would exceed the credit limit"
+        ]);
+        
         $user->increment('credits', $request->credits);
 
         return $user;