If you use the AIO it comes with the high performance backend already set up afaik.

I run nextcloud using the official release without the docket AIO image, but you can just run the high performance backend from docker. This is what I do on my nextcloud server. https://arnowelzel.de/en/nextcloud-talk-high-performance-backend-with-docker

It's pretty straightforward, just run docker container, if you use a reverse proxy much sure the signaling server is properly configured on the reverse proxy and then modify the next cloud settings to point to the self hosted HPB.