How to find out about creating a new domain?

Question

Domain name market

A couple of months ago I registered a domain, bought hosting and uploaded a website. A week later, a call to the phone that is on the site and an offer to promote to SEO.
How did they know? from a hoster, registrar? It is unlikely that such large companies cooperate with small private traders
. I also registered with Adwords, maybe a leak came from there, which is also unlikely

Answer 1

https://whoisds.com/newly-registered-domains