DNS service not running

Can someone tell me how to upgrade from debian 9 to 11 or from debian 10 to 11 with a unifi cloudkey gen 1? I can get 9 to 10 with this website
[Guide] Installing Pi-hole on Unifi Cloudkey v1

Or can someone tell me the command using curl to install an older version of pi hole that still works with debian 10

  • Install Pi-hole using curl -sSL https://install.pi-hole.net | bash
    I am sure there is a way to install an older copy but I do not know the command and no one seems to really have an answer to how to fix pi hole.

I tried that link someone else gave to get debian to 11 from 10 but it did not work for me I couldnt get everything to install.