I would just add that FSD will use the brakes as needed when the car needs to slow down fast. Think coming up to a stoplight and it turns yellow just before you can make it thru the intersection. In (literally) microseconds the car will determine if you're going thru or not and either brake to a stop or continue on.
But, yeah, the car has a brake pedal like any other car. Shoot me a note if you want to drive mine and try it out for yourself
Joe