I am not even sure what an "Avatar use name" is? Are you asking about the available Panda Avatar in the Canvas Student App? If so, then this guide will show you how to create it: How do I create a Panda avatar in the Student app on my Android device?
In looking through those instructions, I note that you can download your avatar, when you download any file, you have an opportunity to name the file. You could then change its name and re-upload it into Canvas to be your profile picture. See, How do I add a profile picture? The uploaded profie picture will be associated with your name, and Canvas will ignore the file name you assigned the avatar.
If I have misunderstood your question, please clarify, and I will try to do better.