You’ll need to re-sideload every 7 days unless you have a paid developer account ($99/year).
iOS 12 is now several years past end-of-life for modern YouTube features. Even with a perfect IPA, you’ll eventually see: youtube ipa for ios 12
If YouTube is essential for you daily, consider saving for a used iPhone SE (2020) or newer — they run iOS 15+ and the latest YouTube app. You’ll need to re-sideload every 7 days unless
After testing several versions, the most stable and functional YouTube IPA for iOS 12 is: If YouTube is essential for you daily, consider
YouTube 17.39.4 (last version supporting iOS 12)
This version still allows:
It does not support: