Resolving Handshake Domains

Handshake domains are new Web3 (blockchain) domains. On their Git, they list NextDNS as one way to be used to resolve Handshake domains in Firefox.  Here is the link:

https://github.com/namebasehq/awesome-handshake#handshake-resolvers

I have downloaded and enabled NextDNS, but still cannot get any of their example domains to resolve (they are listed further up on the Git page)

What am I missing?  Any help appreciated.  Thank you.