IPA files are installer packages for iOS apps:
There are several reasons why users may want to download an older version of YouTube: youtube for ios 12.5 6 download
The official App Store will only let you download a compatible version if the app is already in your "Purchased" history. If you have ever downloaded YouTube on any Apple device using your current Apple ID, follow these steps: Open the on your iOS 12 device. Tap your Profile Icon (avatar) in the top right corner. Go to Purchased > My Purchases . Search for "YouTube" in this list. Tap the Cloud Icon next to it. IPA files are installer packages for iOS apps:
A prompt will appear: "Download an older version of this app?" Tap to confirm. If You Haven't Downloaded YouTube Before Go to Purchased > My Purchases
Several third-party app stores offer older versions of apps, including YouTube:
This is the most reliable way to get an older, compatible version directly from Apple.