I signed up with "Sign in with Apple" but it is not supported on one of my devices
Not all Apple devices support Sign in with Apple but there is a workaround to easily sign in on these devices too!
Journey allows you to add additional sign in method other than the one you originally signed up with, for this case the best option is to add the email/password method to your sign in method.
How to do it
1) Copy your login email address here: See your account and subscription information
2) Reset your password using the login email address you just copied
3) Log in in the device that does not support Sign in with apple using the email and password just set.
For more info about Sign in with Apple check this page https://support.apple.com/HT210318
My Apple ID password doesn't work when I use "Sign in with Apple" on macOS
When you use Sign in with Apple on macOS the password you should use to complete the log in is the computer password, the one you use when you install new software or when you unlock your screen.
This password unlocks the System key-ring that allows the Sign in with Apple to complete.