Did you recently get a new iOS device?
Any Universe site that you create is tied to your Apple ID.
If you recently got a new device and want to access your Universe sites, ensure that you are logged into the same Apple ID as you were on your old device.
To see the current Apple ID associated with your App Store downloads and purchases:
- Open your Settings App and tap your name.
- Tap iTunes & App Stores.
- Check the current Apple ID listed at the top.