This is a known issue. Assuming that you are already signed-in with your AppleID, simply refreshing the page will usually resolve the problem.
If necessary, you can delete associated cookies from your iPad:
Settings > Safari > Advanced > Website Data
Using the Search box, enter apple.com
For cookies and saved data that correspond with apple.com, swipe to the left to delete from your saved website data. After deleting cookies, whilst not strictly necessary, a force-restart of the iPad is recommended:
Force restart iPad (models with Face ID or with Touch ID in the top button)
If your iPad doesn’t have the Home button, do the following:
- Press and quickly release the volume button nearest to the top button.
- Press and quickly release the volume button farthest from the top button.
- Press and hold the top button.
- When the Apple logo appears, release the top button.

Force restart iPad (models with the Home button)
Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
