How to create a sensitivity slider for mouse in game?

ok so as I was adding some code to a movement script I was think I would I make a sensitivity bar like in such as fortnite or any game that uses sensitivity bars process
but I think I figured how to do it I made a simple little one here https://substantial-socks.glitch.me/

alsight so I made the sensitivity slider but Ii can’t fingure out howto put it in the center and I tried margin:auto, margin:0but it didn’t work


after II fixed it