Add all files

app/Rules/Domain.php

@@ -0,0 +1,16 @@
+<?php
+
+namespace App\Rules;
+
+use Closure;
+use Illuminate\Contracts\Validation\ValidationRule;
+
+class Domain implements ValidationRule
+{
+    public function validate(string $attribute, mixed $value, Closure $fail): void
+    {
+        if (!preg_match('/^(?!:\/\/)(?=.{1,255}$)((.{1,63}\.){1,127}(?![0-9]*$)[a-z0-9-]+\.?)$/i', $value)) {
+            $fail('The :attribute is not a valid domain.');
+        }
+    }
+}