Removing old autofill username & passwords

Question

At the bottom of the MS Authenticator screen (on Mobile) is a list of tabs. The second one is "passwords". When I tapped it, I saw old usernames and passwords from up to 15 years ago, some into my router (192.168.1.1) and some to government pages and most to various oft-vidited web sites. Long pressing each one only popped up two options, neither of which is 'edit', 'delete', or 'remove'. MS support / help is non existent. How can these autofil time bombs be cleared out of cyber space??