it’s fairly simple.
You definitely need to change movement mode to a custom one or nothing.
Then you apply impulse based on the slope normal that the capsule component returns from it’s line trace.
Maybe you scale a base speed times that normal to increase or decrease your speed dependent on the slope.
Maybe you set up the W and S buttons to offset the base speed that you apply.
Either way you are relying more on physics then you are on input.