Debian NC installation - php, mysql missing although installed

I am installing NC 25.0.3 on a Debian 11 system with PHP 8.1 and MariaDB 10.5.18 installed and running, but installation page shows that they are not. I reinstalled them several times, even tried older versions with no luck so far.
Can anybody help me what could be possibly wrong?
I am new to NC, not a professional. Any advice is much appretiated!