allow / prohibit access to WebUI

Hello @ all
I would like to restrict access to my Raspberry Pi with Volumio2 to certain users / IP’s. I have already managed to block IP’s of the SSH access relatively easily via the file /etc/hosts.deny. But how do I prevent access to the web interface? I have neither found out which web server is running on Volumio, nor have I been successful in creating a .htaccess file in the folder /volumio/http/www or /volumio/http/www3. If it should go nevertheless with the .htaccess - file: How should it be structured? Does it have to have certain permissions?

Volumio version: 2.729 , Raspberry4 (although this should not matter)

Many thanks in advance


Translated with (free version)

keiner eine Idee?
nobody one idea?