3-5 x15 lateral single leg squat of box

Then

3 x 30 sec squat hold, knee at 90 degrees, immediately after that 15 max reps of squat jumps

In single leg squats, focus on the knee tracking along the toes while squatting. Minimise the use of the supporting leg.

In squat hold, focus knees out, do not go too deep or too high. In squat jumps focus on full hip extension, rather than on the height of the jump.

Use weight as you feel.