True dead pedal will mount directly to a frame member or other solid structure. Putting carpet between the frame and the pedal surface defeats the purpose of the dead pedal..giving direct chassis feedback to the driver.
Note, if you have a 2020 or later model with the carpet, you need to remove the adhesive backing (came off pretty easily for me), and add some heavy-duty velcro strips to the back. That way, it will stick nicely to the carpet. If you look at the reviews on the amazon link above, you will see a picture of someone who removed the adhesive and added Velcro.
The picture on Amazon only shows they added velcro on the upper & lower parts of the dead pedal. I have that same dead pedal and I put industrial strength loop velcro on the entire pedal, including on the slide lip that bends (cost like $5 from Home Depot), and it sticks well to the carpet and will not move at all. I wish I took pics of that but I didn't. Even when I've put a lot of force on the dead pedal (like when braking hard), it doesn't shift or move at all.
Here's my Amazon dead pedal with 2017-19 floor mats, on my 2020 SR+ (before I wrapped my dash).