Hello, my problem is that I can not change my username in the game of Trine 4, I can not find the option, because I played Trine 1, 2, 3 and yes I could do it, but now no, is there any trick, because today I was playing with a friend in a private game, he has his game on steam and he gets his steam username obviously. To me instead I get the name of my pc, and I can not change it, how could I change the name?

I hope someone can help me :)