added nullable validation

app/Http/Requests/Expense/Payment.php

@@ -29,7 +29,7 @@ class Payment extends Request
             'amount' => 'required',
             'currency_code' => 'required|string|currency',
             'currency_rate' => 'required',
-            'vendor_id' => 'integer',
+            'vendor_id' => 'nullable|integer',
             'category_id' => 'required|integer',
             'payment_method' => 'required|string',
             'attachment' => 'mimes:' . setting('general.file_types') . '|between:0,' . setting('general.file_size') * 1024,

app/Http/Requests/Expense/Vendor.php

@@ -40,11 +40,11 @@ class Vendor extends Request
         }
 
         return [
-            'user_id' => 'integer',
+            'user_id' => 'nullable|integer',
             'name' => 'required|string',
             'email' => $email,
             'currency_code' => 'required|string|currency',
-            'enabled' => 'integer',
+            'enabled' => 'integer|boolean',
         ];
     }
 }