I was searching through commands on Niche when I saw this, I don't know if everyone knows about it. If you want to reset your achievements (for some reason) then press f1 and alt, type ResetAllAchievements_BEWARE and then press esc. I haven't tried it, but it probably works? I'm not testing it out. I hope this helps? (It likely won't because most people like keeping their achievements, but someone might want to do some over again)