thank you sir, another question, are you using the domain for anything else other than receiving zaps?
I used fiatjaf's bridgeaddr (https://github.com/fiatjaf/bridgeaddr)
Most of it is explained there. Let me know if you run into any snags
Discussion
Once you set a domain (or subdomain) in a CNAME record to another address, all traffic to that domain (or subdomain) will be forwarded to the address in your CNAME record.
In my case I just used a subdomain in my CNAME record.
So, I have other subdomains free to do other things
So invoice.gerbils.online is exclusively used for mapping LN addresses to my LND