How do I market my new product

Hey, y'all! I just built a new product. It's a directory listing that helps people find nearby martial arts gyms.

My problem right now is that I don't know any ways to really market it. Do I focus on SEO and let it rank and rely on ads?

Do I reach out to gym owners and charge for a listing?

This feels like a chicken and egg -- or cold start -- problem.

If you want to check the site out here is the link -- https://dojoz.club/

Thanks in advance!