Valid Apple ID Not Accepted For iCloud On MacBook Air

I've tried to sign in to iCloud on my MacBook Air for the first time using my Apple ID that I have used for years.

It won't accept that ID.

The message I get is the ID I used is not an email address.

The ID I have used for years has never been an email address and has always been the same ID and password.

I've used this ID to sign in to iTunes, and FaceTime on my, iPhone, and iPad.

With the exception of iCloud, I use that ID to sign in to the same apps on my MBA.

It also works to sign in to iTunes on my desktop PC.

Used the ID to sign in to this site on my MBA .

Why is iCloud on my MBA asking to use my verified email as my Apple ID and not accepting the ID I have used for years on the other Apple devices?