Using Nginx SSL Proxy to forward different domains to different services

I have the Nginx SSL Proxy and Duckdns addons set up on my Home assistant instance, allowing me to access it externally with SSL from a domain such as hass.duckdns.org. I have port forwarding set up on my router so that port 443 (for SSL) is forwarded to my Hass instance, as port 443 is being monitored by Nginx.

I also have Bitwarden RS set up as an addon, and I can currently access this externally using hass.duckdns.org:7277.

Is there any way to change this so that I have another domain such as hassbitwarden.duckdns.org, which, when the domain is entered (without the need to append the specific port), the Nginx proxy picks this up, and, based on the url, routes this domain through to Bitwarden_RS?

In summary:

hass.duckdns.org → Home Assistant Instance
hassbitwarden.duckdns.org → Bitwarden RS Addon

Nginx can definitely do this, but I don’t think the HA addon has that functionality.
Bottom-line: If you want this, you’ll have to install your own nginx, not the HA version.

Correct. The “NGINX Home Assistant SSL proxy” add-on would help you access HA and HA only.

Switching to the other add-on “Nginx Proxy Manager”, with some tinkering, would help you achieve what you are looking for.

You will want to disable the “NGINX Home Assistant SSL proxy” add-on, and make changes to duckdns add-on.