why validation error message received even if i provide all keys laravel code example

Example 1: how to add an custom error to validater error in laravel

if (request('event') == null) {
    $validator->errors()->add('event', 'Please select an event');
}

Example 2: laravel validation

$rules = ['name' => 'unique:users,name'];

$input = ['name' => ''];

Validator::make($input, $rules)->passes(); // true