iOS does not allow "downgrading" standard App Store apps. You must delete the current version and sideload the old one.
Before you click any link, understand the modern threat landscape. Hackers know people want old versions of popular apps. download youtube ios 1257 link
If you have ever downloaded YouTube in the past using your Apple ID, you can often download a compatible older version. on your iOS 12 device. profile icon in the top right corner. (or "My Purchases"). Search for "YouTube" in this list. Cloud download icon iOS does not allow "downgrading" standard App Store apps
The request for a "YouTube iOS 1257 link" cannot be fulfilled directly because version 1257 does not exist . The user is likely seeking version 12.57 (from 2020). However, even for version 12.57, there is no direct, permanent "link." Hackers know people want old versions of popular apps