DNS error: A DNS zone for this domain already exists on NS1, the DNS provider backing Netlify DNS

I bought and registered the domain postsstation.com with Wordpress. I’m trying to move the domain to my Netlify app, but I’m getting the message “A DNS zone for this domain already exists on NS1, the DNS provider backing Netlify DNS. Please contact NS1 with the domain name for support.”
NS1 isn’t answering me and their customer support seems limited to nonexistent. My website name is https://poststation.netlify.app Is anyone able to help me set up Netlify DNS records for my domain?

Have you read the following support-guide?

Hi unfortunately the first step is reaching out to NS1. This likely that the domain you’d like to add exist in a parking zone. They will be able to assist you.