I have recently activated two-step authentication for my Yahoo! e-mail account. I am now no longer able to use iOS Mail (on iPhone) or Apple Mail (on macOS) even though I have created third-party app passwords as recommended by Yahoo!.
The error messages read "Invalid Password. Please try again." (in
Re-enter Password) and "Wrong Password. Try again." for iOS Mail and Apple Mail respectively.
So how can I successfully configure Yahoo! third-party app passwords into iOS Mail and Apple Mail?