Not all IPAs are created equal. If you use a file that is too new, it won't install (invalid entitlement). If it is too old (version 1.0), the server-side API will reject it. You need the "Goldilocks" versions.
Open Sideloadly. Select your iOS 9.3.5 device from the dropdown. Drag the IPA into the application box. Enter your Apple ID (Create an app-specific password if you have 2FA enabled—you will need to visit appleid.apple.com to generate one). youtube ipa for ios 935
Consequently, users must find a —a manually downloaded file that can be installed using third-party tools. Not all IPAs are created equal
Do you have access to a (iOS 14+) to use the purchase history trick? You need the "Goldilocks" versions
To install an IPA file on an iOS device, you typically need to use a computer and a tool like Cydia Impactor or AltStore. Here's a basic guide: