After being forced to reset my iPhone (due to an unrelated app crashing), I wanted to access 1Password.
iOS would not open 1Password unless I first entered the password for Apple ID.
That password, naturally, is under wraps in 1Password.
I've never had this issue in the past. If this had occurred while I was "on the road" without access to my Mac to get the AppleID password I would have been completely diddled.
This may have occurred following an update to 1Password - I'm not sure.
1Password Version: 7.3.6
Extension Version: Not Provided
OS Version: iOS 12.3.1
Sync Type: Dropbox