Yes, but I an idiot when it comes to tech tbf, So would be delighted to get advice about how to change it
I have access to the control panel, which is different to what you see, I assume it's the following: Top right by pic.....Personal details, Advance options, Username change.
Ok, might be the way I've reset it. So I put your account into test, and could see you didn't have the function. So I've made a change and can see it now, so try again.