$validator = $request->validate([
'username' => 'required|string',
'password' => 'required|string'
]);
if ($validator->fails()) {
return response()->json(['errors'=>$validator->errors()]);
}
<form method="POST">
<input type="text" name="name1">
<input type="text" name="name2">
<input type="text" name="name3">
<button type="submit">Отправить</button>
</form>
<?php
$name1 = $_POST['name1'];
$name2 = $_POST['name2'];
$name3 = $_POST['name3'];
?>