Next Cloud Setup Issues

We are currently trying to setup a nextcloud solution for one of our customers. Unfortuantely we are having a couple of issues due to not being able to connect the machine to the internet. I suspect this is due to incorrectly configured DNS/Proxy server within nextcloud.

Can you provide me with a guide for viewing/modifying the DNS/Proxy settings.

Many thanks,

Managed to resolve the DNS issues by following https://askubuntu.com/questions/973017/wrong-nameserver-set-by-resolvconf-and-networkmanager. Currently having issues pointing the server to our internal proxy server. Without this we cannot get internet access to download updates/recieve AV definitions ect.

Cheers