I use Cloudflare tunnels for this very reason, you can protect access to the page behind a login (I use azure AD).
It basically acts like a reverse proxy allowing me access to those local resources without anything being installed on the client computer.
I use letsencrypt a lot, if firewalls are an issue I’ll use dns authentication.
If you are struggling and need a quick fix, the free tier of zero ssl will do a similar thing
https://zerossl.com/
I used it to get a cert for my printer