How to create custom authentication in laravel 8?

PHP Snippet 1:

protected function validateLogin(Request $request)
{
    $request->validate([
        $this->username() => 'required|string',
        'password' => 'required|string',
    ]);
}

protected function credentials(Request $request)
{
    return $request->only($this->username(), 'password');
}

//Mention your username here
public function username()
{
    return 'user_name';
}