Because the security of the iOS system determines that it only grants permissions to a fixed single account, instead of granting permissions to two mobile phones at the same time, you can switch between two mobile phones, but it is more difficult to enjoy data. Although you can't enjoy it, you can share it. The operation steps are as follows:
1. Tap the invitation, for example, on the lock screen or in Notification Center or Health.
2. Click "* * * Enjoy" at the bottom of the screen.
3. Then tap View in the invitation at the top of the screen.
4. Click "Accept".
5. Then click "Finish".