Listener ERROR Raspberry Pi running DNS over HTTPS on LAN

Running Debian Stretch on a Raspberry Pi configured to use DNS over HTTPS on my home network for a final project at school. Not very experienced with Linux, but managed to get it installed. When I checked to see if it was running properly I got an error message after entering “sudo cloudflared proxy-dns”

*Failed to start the listeners error="failed to create a UDP listener: listen udp 127.0.0.1:53: bind: address already in use"

Apologize if the picture doesn’t help. But I can get other screenshots if they are needed.

Says it already. You already have another application running on that part (probably the default named). You will need to stop that application first.

HI Sandro thanks for helping… I’m sorry, I don’t know which application it is referring to. All I see is “Failed to start the listeners”… and that the address for “127.0.0.1 port 53 udp” is already in use, but I don’t know what is using it or how to find out what is using it.

Is it just this address and port or is it all of the listeners?

How do I determine what is using this address? Is it “bind” or the line above it that has “dns://localhost:53” the address that’s already in use?

Would I use the “top” command to kill a process or application or is it in a config file?

Do I have to make any adjustments to ufw or a config file?