Who can sign an app with a developer account (IOS)?

Question

Apple Xcode

I found an old iPad 2 and, as often happens with iCloud, I could write to apple support to unlock it, but I could not find a receipt or a box. I found a way on the Internet with a jail, but to install, the application must be signed by a developer account, which I unfortunately do not have. I would be grateful for help.
https://4pda.ru/forum/dl/post/16870354/Phoenix5.ipa