Hi @swinfield
First off as a disclaimer, I’m not claiming that this is the best or most supported method but it is a way I managed to get my letsencrypt certs to work (in my current environment I do letsencrypt certbot directly on my host server and then mount the certs into my docker container for Caddy. Should work for your GoDaddy certs too
Check the tutorial I posted here : Custom SSL/TLS certs