A live and a backup server hosting same domain and using the same certificate...how to set up?

[Bruce5051]

Continuing the discussion from Two hosts, same domain,:

@serverco

Two separate certificates is trivial ( simply run certbot, or your preferred client ) once on each webserver host.

But that would not (likely) be using the DNS-01 Challenge

Challenge Types - Let's Encrypt

And kindly wait for more knowledgeable Let's Encrypt community volunteers to assist.