When i try to start the app.js is just get:
{}
Do not run that service with root privileges.
In case a vulnerability is found in that service and an attacker gets shell access the attacker gains access to the whole system.
You may have a look to
were I uploaded my configuration for nginx and for the service files that are used to startup the service.
Besides that part of the configuration you config.json file might be of interest for the analysis.