If you’re using the Roblox app on an Android, iPhone, or iPad, you may have to click three dots instead.
You must have 1000 Robux to change your username. If you don’t have enough Robux, you’ll see a pop-up that says “Insufficient Funds. " Click Buy if you want to buy some Robux, and then follow the on-screen instructions to pay. If you haven’t already linked an email address to Roblox, you’ll see a pop-up message telling you to do so now. Click Add Email if you see it, and then follow the on-screen instructions to add your email address.
Other players will still be able to see your old username. Don’t choose a name you regret. It’s expensive!