Once you've downloaded the YouTube IPA file, follow these steps to install it on your iOS device:
: After installation, you may need to go to Settings > General > Profiles & Device Management to "Trust" the developer profile.
Wait, but maybe the user can't update their iOS because of hardware limitations? Older iPhones might not support newer iOS versions. That's a valid concern. In that case, the essay needs to acknowledge that, but still encourage them to check for iOS updates first before proceeding with any workarounds.