To redeem a code on Roblox, you must first create an account. If you have already created an account, then follow these simple steps!
1) Open up the game and go to your profile page.
2) Scroll down until you see Redeem Code in the bottom right hand corner of your screen. Click that button and enter the code into their field where it says Enter Code Next to Show Your Game Pass Now (RIGHT). Then click Continue!. The next step will ask if this is for one or multiple accounts and select one.
3) You may now start playing with all of your new stuff!