maxi It's not uncommon for a control panel to use a different PHP version from what you've selected for a domain, which sounds to be the issue you're having.
Depending on the control panel any of the following could be a fix:
- If it gives you a PHP version selector for cron, use that
- Try specifying a different PHP binary to use in the cron job (something like
- Remove any PHP versions less than 8.1 to ensure it can't use an incorrect version
If all else fails you can contact the developers of your control panel and ask for assistance or utilize an external service to remotely call the cron job after enabling the endpoint via the cron settings in FOSSBilling.