I was wondering how I could change my username to match my IGN since as far as I know I can only change the name that appears when you click on someone’s profile
You should be able to match the discord name to your IGN by running /force-sync in discord. If you mean discourse (which it seems like, your spelling leaves it open to interpretation though), you can go to your profile (e.g. via sidebar->summary) then click on the settings tab (the gear) and change the username.
They are 11 and don’t have Discord but I can change their name