Head over to the Roblox website and create an account for yourself. Then all you need to do is click on the 'Avatar' tab on the left side of the screen, where you’ll see your avatar ready to go.

You might need to edit it first before uploading to the Roblox Studio platforms, as it needs to be under 1,000 x 1,000 pixels to work. If your image is larger than that, it'll blur, and that's not ...