Bookstack container questions

If you intend to use this application behind a subfolder reverse proxy, such as our SWAG container or Traefik you will need to make sure that the APP_URL environment variable is set to your external domain, or it will not work

What does this mean for me if I’m just planning to use nginx proxy manager on baremetal?

I’ve run the command for generating the app key but it’s given me both a sha256 string and a base64 string, which one do I use?

that would be a question for NPM or bookstack.