Based on the error message you received, it seems that you are using the Pest testing framework instead of PHPUnit. Pest is a testing framework that is built on top of PHPUnit and provides a more expressive syntax for writing tests.
To resolve the issue, you can try running the command ./vendor/bin/pest instead of ./vendor/bin/phpunit. This should execute the tests using the Pest framework.
If you still encounter any issues, make sure that you have installed Pest correctly by running composer require pestphp/pest --dev. Also, check your phpunit.xml or pest.php configuration files to ensure they are properly set up.
If you have any specific code examples or error messages, please provide them so that I can assist you further.