Tax wealth, not work

Use Caddy for reverse proxy. It’s magic. Just put in config the subdomain/domain and localhost port to point to, it will fetch and configure and keep certificates up to date with zero effort. You’ll forget certificates exist. It just works.

One easy way to test accessing your site externally is use a free web proxy to try to load it.

For example (not a personal recommendation, just a random search result) https://wproxy.net/

Been with VoIP.ms a long time. So long that I don’t really know what alternatives are out there. It works for me. I’ve never required any support though, so not sure about your activation issue.