It doesn’t usually matter what the service is, the basic concepts are the same. If you want to access a service you host on your internal network from another external network you either need to use a VPN to securely connect into your network, or expose the service directly. If you are exposing it directly you should put it (or a proxy like NPM) in your DMZ. The specifics of how to do this though will vary from service to service and with your specific network config.