This is a good reference to do warm ups before doing a One-Legged King Pigeon Pose by Chelsea Jackson.
5 Ways to Warm Up for One-Legged King Pigeon Pose
One-Legged King Pigeon Pose (Eka Pada Rajakapotasana) engages multiple muscles that constantly contract, like the hip flexor and groin muscles. Mastering this deep hip opener and backbend can help stretch these areas and release tension. Use the following five poses from teacher Chelsea Jackson to warm up safely for One-Legged King Pigeon.
Read here the full article 5 Ways to Warm Up for One-Legged King Pigeon Pose
There is a instructional video how to do warm ups before doing the pose One-Legged King Pigeon
Hope this article and video help you in your journey in yoga poses. go here for more info about yoga.