Move NCP instance from port 80/443 to any other ports

I am using the nextcloud pi instance setup well on my raspberry pi 4B. However, I want to run pi-hole as well on it and it requires the 80 and 443 ports to be free. So, I want to have have the ncp to run on ports 81/444 (for example). I have tried updating the .conf files in the apache2/sites-available folders, however that could not fix it.

Any leads on how to get it done or if there is anything that i am doing wrong, please let me know. Thanks for your time.

You might also need to edit /etc/apache2/ports.conf and restart the service.
Make copy of files before editing, so you can revert if it breaks your setup.