SearXNG + Nginx Nginx Proxy Manager config

Hello,
I’m running SearXNG and Nginx Proxy Manager (NPM) both from TrueNAS repo. NPM works fine with all my apps, except SearXNG. Any idea what special configuration I need to do in SearXNG or NPM to make it works?
In the SearXNG settings I set up the Additional Environment Variables SEARXNG_HOSTNAME as https://sear.mydomain.tld
In NPM I did try with or without webSocket.
Whoogle is working fine with the same settings for example.