An iCloud account and an Apple ID are the same thing.
Click on this link to find out how to 'Sign in with your Apple ID' --> https://support.apple.com/HT201762 "After you log in, you can use the App Store, iCloud, iMessage, Apple Music, Apple TV+, and more."
Error messages:
- Cannot reset password
- This Apple ID is either not valid or not supported.
- This Apple ID is not active.
- we can’t find the Apple ID matching this information
There is no Apple Support document specifically addressing your message that I can find but these links have been Recommended by Apple ( https://discussions.apple.com/thread/7417834 ) and others with this problem:
If your Apple ID is locked or disabled --> https://support.apple.com/HT204106
Contact Apple for help with Apple ID security --> https://support.apple.com/HT204169