Kart will rotate one of two ways:
Throttle: lift or throttle reduction prior to turn in, proportionately reduces the load going through the kart and sends the energy back off the nose. The subsequent turn in can then be modified via slip angle as the lift allows you to rotate the kart beyond the turn in angle and set the turn. Think lift off oversteer.
Brake: Brake assisted rotation. Opposite of lift. Typically a “brushing” of the brakes, just prior to turn in. Literally trying to get the interlock between tire and surface to slightly release, (not a skid). Timing the brake brush to coincide with turn to push nose down and into track while back tires slightly release, rotate.
It seems to me that we drive more with throttle or brake than the steering wheel. It seems to me that the turn inputs are suggestions and that the majority of the turn involves pedal inputs. The steering wheel allows you to “tip” the mass of the kart in a new direction, but it’s the feet and how you manage the weight sloshing around, and subsequent grip, that defines the turn.