How can I transfer a squarespace domain to Netlify?

Hi, I tried to transfer my domain from squarespace to Netlify
Squarespace is giving me an authentification code, but there is no place to enter it in Netlify.
When I try to setup the Netlify DNS for my domain, I get this error message : A DNS zone for this domain already exists on NS1, the DNS provider backing Netlify DNS.
Thanks for your help!

There are two ways to connect a custom domain to a Netlify site.

Netlify DNS means using Netlify as the DNS service provider. The external DNS keeps the DNS resolution with the existing provider - which is normally the domain registrar but not always.

If you are moving an existing domain name to Netlify DNS -especially if you have an email service configured for it - please be be sure to copy all existing records to Netlify before changing the name server (NS) records to point to Netlify. There is more about this topic here.

If you are using the external DNS method, the existing DNS records remain active so no records need to be copied.

Please let us know if there are other questions about this and we’ll be happy to answer.