Source: Chris Hoffman, HowToGeek.com, February 13, 2018
Fill Passwords in Safari and Web Views
Everyone should use a password manager, and third-party password managers like LastPass, 1Password, or Dashlane work better on an iPhone or iPad than you might think. You can directly autofill passwords on websites and apps using a share sheet action. It’s just hidden by default.
Your iPhone or iPad offers integrated password autofill, too…as long as you use Apple’s keychain for your passwords.