Buffalo Bills’ safety Damar Hamlin is challenging Americans to learn how to perform CPR.

Hamlin’s life was saved when he received CPR and was resuscitated on the field during a game between the Bills and Cincinnati Bengals. Now, the 24-year-old is partnering with the American Heart Association to kick off what’s being called Damar Hamlin’s “3 for Heart CPR Challenge.” 

The first step in Hamlin’s challenge is to go to heart.org/3, where people can watch a video explaining how to perform hands-only CPR. For the second step, Hamlin is asking people to donate to the American Heart Association for CPR awareness and education. For the third and final step, Hamlin wants you to ask three people to complete the challenge.

Hamlin personally challenged LeBron James, Tom Brady and Michelle Obama to do his 3 for Heart CPR Challenge.

It’s only been four weeks since Hamlin collapsed after making a tackle on Bengals receiver Tee Higgins on “Monday Night Football” in Cincinnati. Hamlin suffered cardiac arrest and was treated on the field with CPR and AED for nearly 10 minutes. The Bills’ safety was eventually placed in an ambulance, which took him to University of Cincinnati Medical Center.

On Saturday, Hamlin spoke publicly for the first time since nearly losing his life during an NFL game. Hamlin thanked those who saved his life and expressed gratitude for all the support that he’s received in a lengthy Instagram video.

According to the AHA, interest in learning how to perform CPR increased in the aftermath of Hamlin’s public medical emergency. The number of pageviews to Hands-Only CPR content pages went up by 620%.