The connection is not redirected

[Piero24]

I have a computer with Ubuntu Server 20.04 on which I installed casaos and through this I installed adguard home. After setting everything up I entered the IP address of the Ubuntu server (192.168.1.50) in the DNS settings of my devices to test but it doesn't work. but the connection is not redirected to adguard as no query appears in the control panel.

I used the command: nslookup google.com that return me this:

usr@name:~$ nslookup google.com
Server:		8.8.8.8
Address:	8.8.8.8#53

Non-authoritative answer:
Name:	google.com
Address: 142.251.209.46
Name:	google.com
Address: 2a00:1450:4002:411::200e

And as you can see it points to Google DNS. I think it's because of the file: /etc/resolv.conf
Which has the following DNS:

nameserver 8.8.8.8
nameserver 8.8.4.4
# nameserver 192.168.1.50

Does anyone have an idea on how to fix it?