How do I recover lost passwords on iPad?

The tags appended to your post suggest that your iPad is running iPadOS 18.

Having updated to iOS/iPadOS 18.x, you will no longer find your saved Passwords in iPad (or iPhone) device settings. All saved passwords have been migrated to the new Passwords App which you will find on one of your Home Screens, or from the App Library.

Like iPadOS 18, iPadOS 26 (the most recent major version) also uses the new Passwords App.

If when opening the Passwords App you only see a blank page, this is a bug sometimes seen upon using this App for the first time. If seen, the problem is easily resolved...

Assuming that the Passwords App has been added to the Dock - and with the Passwords App open to the unexpected blank page - swipe upwards from the bottom of the screen to expose the Dock; tap the Password App icon - then tap New Window. This should open another Passwords App window showing your stored Passwords.

They could be anywhere. How did you store them? That might at least give us some hint. Were they in Keychain? Were they in Notes? Were they hidden as part of a song title, or as somebody's name in Contacts?

You're very welcome. I guess we found and resolved the problem.

Having found the Passwords App - and cleared the bug - you simply close the blank Passwords App window - or both. Next time you open the App, it will open as it should.