use Symfony\Component\Validator\Constraints as Assert;
use Chaman\Validator\Constraints as CustomAssert;

class Demo
{

/**
 * @var string
 *
 * @Assert\NotBlank
 * @CustomAssert\MongoId
 */
private string $mongoId;

use Symfony\Component\Validator\Validation;
use Chaman\Validator\Constraints\MongoId;

...
$validator = Validation::createValidator();
$constraint = new MongoId();
$id = '612e33884726a713fd31009b';


$violations = $validator->validate($id, $constraint);
if (!count($violations)) {
    ...
}