403 error while working in the system (in Plesk)

[Yunus]

I installed Revive Adserver version 5.5.2. There were no errors during the installation. I accessed the admin panel, but when I try to create a zone, I get a 403 error.

The lowest PHP version available on my server is 8.2.17.

I even manually created a zone via phpMyAdmin, but when I try to assign a banner to it, I get another error. All errors seem to be related to permissions.

What can I do to fix this?

Error:

Server Error
403
Forbidden
You do not have permission to access this document.