sit with forearm supported, palm up, actively extend wrist upward against gravity and return to neutral
Sit on the chair, rest the foresrm on the arm rest such that hand is off the arm rest and palm facing towards the ceiling. Hold the forearm with other hand, move the hand towards the floor, move the hand back to starting position and repeat.
Nothing here is a prescription. Your physiotherapist decides which of these are yours, and when.
