Some teachers may say your shin needs to be parallel to the front of your mat in pigeon pose, but in my experience as a yoga instructor, as long as your hips are squared to the front, that’s what matters most. If you’re struggling to get comfortable in this posture, it can help to situate a block or bolster under the hip of your front leg.
If it’s still too much, even with a block, consider trying a reclined figure-4 stretch. And of course, be careful if you have any chronic issues with your hips or low back.
As you get comfortable in this pose, you can lower your head down, either resting your forehead on your hands or stretching your arms out straight toward the front of the mat, bringing your forehead to rest on the ground. Breathe deeply into the sensation of the stretch in your hips, and don’t feel the need to stay longer than is comfortable.
If you want to kick it up a notch, consider trying king pigeon, also called mermaid pose, or eka pada rajakapotasana.