If you're getting the error below when trying to Set up Netlify DNS for your Squarespace domain, read this post.

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

Go to your Squarespace account and click in the domain you want to configure.

1 - Advanced Settings > Nameservers Settings

2 - Make sure you have "Use custom nameservers" selected. And declare only the nameservers of Squarespace (This is needed to SSL certificate to work)

3 - Now go to "Edit DNS".

4 - Add the following two records. Make sure to declare the correct url of Netlify app. (In the first line, the IP 75.2.60.5 is the same for all).

Now you can go back to your Netlify account, and click at the "Domain management" tab, and see that your domain is working as expected.

Before:

After:

The information above can be seen in the Netlify Forums/Tutorials, but not this straight forward. Thats why i decided to make this post.