Do all Activision accounts have numbers?

So I just got warzone, and I need to create an Activision account, as this is the first time it's required. I try to enter in my information, but it says invalid

I'm trying to make an activision account and it keeps saying invalid user. But doesn't ask for a username. Solution? : r/Warzone

I started playing the beta today and Activision automatically signed me in to some random person's account. Has this happened to anyone else? : r/modernwarfare

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