Load into Super Muscle Simulator from the Roblox game page.; Once in a lobby, tap the Shop icon denoted by a basket. Scroll down to the very bottom until you see a Codes section (which isn’t ...

Launch Muscle Race Simulator in Roblox. On the left side of the screen, you should find the Codes button (ABX). Click on it, a text box will open. Copy and apste the code you want from this page.