Hamstrings, with looped Strap

Loop your Strap around your leg and then a suitable anchor point. Avoid stepping into a closed, anchored Strap.
Relax your leg. With your unaffected leg ahead of the other, lean away from the anchor and let your body weight create the required pressure.
To increase the pressure, transfer your weight onto your back (affected) leg.
For more pressure, push away from the anchor with your unaffected leg.