Vaultwarden in https behind Nginx Proxy Manager


I have vaultwarden installed in docker image and Nginx Proxy Manager (NPM) in another docker image on my QNAP TS-673A. The vaultwarden has the ip

NPM listens on this two ports :


On my router the port 443 and 80 are already used by others services, so i have set up :

on my router 16897 forward to 35443 on the ip on my NAS

I can access to but not to

In NPM i have set up the proxy with the domain, when i try i have the let’s encrypt certificate but i have an error page : 502 Bad Gateway

What i have missed in the configuration ?

Thanks by advance