Hello 13m3,
In order to change your username in-game you must fill out this request: https://forms.gle/J5r8hqQmUcBHYiYq7
Also, have you joined our Discord Server yet? It's the best way to get in touch with us and the rest of the HMM Community!
Join here: https://discord.gg/heavymetalmachines
See you in the Arena!
Xanthos