How to stretch psoas while sitting?

Hello there, I'm curious about how one can stretch their psoas muscle while seated. As someone who spends a lot of time sitting down, I've heard that stretching this muscle can help alleviate back pain and improve posture. Could you elaborate on some effective seated psoas stretches? Perhaps you could mention a few easy-to-follow steps for each stretch, as well as any precautions or tips to keep in mind. Thank you in advance for your insight!