Yunohost behind reverse proxy

My YunoHost server

Hardware:
Raspberry Pi3B

YunoHost version:
4.2.5.3(stable)

I have access to my server : Through SSH | through the webadmin

Are you in a special context or did you perform some particular tweaking on your YunoHost instance ? : no

Description of my issue

Hello !

I recently tried yunohost for the first time and I’m really happy with it.
It is installed on a RPi3 and it mostly works fine, appart from several apps like Librephoto and a couple others that I’d like to use. I’d also need NextCloud bit it runs slow.

So I bought a RPi4B4 and tried another setup with OMV/Docker/Portainer.
I’d love to keep using yunohost for the apps I already use with it.

So I use nginx proxy manager on my rpi4 and I can access the admin panel through it, but not the UI (/yunohost/sso/)

Is this something due to Yunohost or Nginx proxy manager ?
NPM is pretty straight forward, and I don’t see if there more I can do.

Anyone already tried this kind of setup here ?