403 Error While Trying to Add Domain to Netlify DNS

I’m having trouble registering a custom domain for my Netlify site called anthias.netlify.app. When I go to the “Domains” tag on my team page, and try to add my custom domain, which is “anthias.xyz”, I get this error:

I registered anthias.xyz on google domains, but would like to use Netlify DNS so I can take advantage of branch subdomains. I have tried pointing the nameservers on google domains to dns1.p01.nsone.net, dns2.p01.nsone.net, dns3.p01.nsone.net, & dns4.p01.nsone.net but am still getting the same error. I’m not even sure if these are the right nameservers though because I’m unable to go to step 2 in adding a domain to Netlify DNS.

Any help would be appreciated, thanks.

Bump on this, I would really appreciate any help.

Unfortunately, that’s an error from NS1 (our DNS Provider) and you might want to contact them to clear the zone for you to use.