If there is anyone trying to get a new invitation code to the forums look no further. Honestly took me forever to figure out how to do this so figured I’d post it.
Go to Support on eso website
Go to Additional Support at the bottom
Select your platform
Select “Account” and then choose the sub category “I need help with a forum account”
Select “Need invitation to forums”
Select “Next” at the bottom of the screen.
Choose to contact customer support and ask them to send you a new invitation code. They contacted me with a new code within 10 min.
Hope this helps!