I don’t remember the exact procedure for this, but here’s the summary. You’ll first want to install sidestore or sidestore + livecontainer. Computer needed for that. You’ll also want a stock YouTube ipa file that you can then mod with YouTube Plus or similar utility.

You’ll have to update livecontainer (if you installed it) and YouTube every 7 days unless you have a dev license but Sidestore does it with a single button press in-app so it’s not that inconvenient. You can install ipas within sidestore (limited amount at a time) or livecontainer (as many as you want I believe, but it’s more complicated) without connecting to a computer once the initial setup is done