How do I find out what my iCloud username is
Where do I find my iCloud username
iPhone XR, iOS 15
iCloud uses your Apple ID and password. If you only have one Apple ID, it would be the same ID and password as you used to log into this forum. If you have another and have forgotten the ID or password, see the following:
If you forgot your Apple ID email address or phone number - Apple Support
or
If you forgot your Apple ID password - Apple Support