Can't make a custom Signature validator class [Laravel 8 Spatie Webhook Client]

I am a beginner and I'm trying to make a custom signature validator class and following the Spatie documentation I made the file CustomSignatureValidator.php which implements Spatie\WebhookClient\SignatureValidator\SignatureValidator but I'm getting the following error:

App/Handler/CustomSignatureValidator is not a valid signature validation class. A valid signature validator is a class that implements Spatie\WebhookClient\SignatureValidator\SignatureValidator

This is how it looks like:

 <?php
    
    namespace App\Handler\CustomSignatureValidator;
    
    use Illuminate\Http\Request;
    use Spatie\WebhookClient\Exceptions\WebhookFailed;
    use Spatie\WebhookClient\WebhookConfig;
    use Spatie\WebhookClient\SignatureValidator\SignatureValidator;
    
    class CustomSignatureValidator implements SignatureValidator
    {
        public function isValid(Request $request, WebhookConfig $config): bool
        {
            return true;
        }
    }

I've also tried using

use Spatie\WebhookClient\SignatureValidator\SignatureValidator as SignatureValidator;

But i am also getting the same error.

If you could tell me what am i doing wrong i would really appreciate it.