An Two-factory of iPhone X to iPad 1th

Hello! I want to access my ipad 1 through the same account running on ios 5.1.1 so I can’t enter the two-step verification code from the iPhone X to the ipad due to the incompatibility of the operating system versions. I want you to solve this issue and I went under one account to all my devices, whether they are old or new, I want to use them, especially the magic of synchronization of one system !!!