If you have a direct IPA link and want to install it without the App Store, you will need a "sideloading tool". Common methods include:

Sideloaded apps often crash or expire every 7 days unless you have a paid developer account.

Enable creators/dev teams to create, manage, and share iOS build install links (TestFlight or direct enterprise/adhoc) from within YouTube Studio’s developer/test builds area for easy beta testing.

: Some "YouTube++" or similar IPAs include unofficial tweaks for ad-blocking or additional creator tools, though these are typically for the main YouTube app rather than Studio. Critical Risks of Unofficial Links

Are you trying to install this on a or looking for a modded version with extra features?