I am not privy with nginx configurations.
My NAS is running openmediavault version 8, which includes nginx and for my own convenience until now I have managed creating proxy hosts for a small number of docker containers using the nginx proxy manager docker.

I am having trouble understanding the installation guidelines: Reverse Proxy configuration and don't understand what I am supposed to do:

• within compose
• within sync-in-docker/config/nginx
• and/or within nginx proxy manager (NPM)

E.g. In NPM have already created a reverse proxy for sync-in.MYDOMAIN.TLD, SSL terminated, and this works.
Is that the right way and how do i match/connect this with the Sync-n configuration to make things work?

It's confusing to me and I would appreciate some nudges.