Use Home Assistant with dedicated OwnTracks instance

Hi,
I’m using Home Assistant OS and have a dedicated OwnTracks instance which I use for device tracking.

I don’t want to use Home Assistant’s OwnTracks integration since I’m connecting to my HA instance via a VPN and want to be able to track my devices from outside a VPN as well.

My question is: How do I setup HA to listen to my Owntracks instance via MQTT to get device locations inside HA? I’ve already setup Owntracks to connect to my (also dedicated) MQTT instance and I’ve also setup HA MQTT to listen to that instance.

Thanks a lot in advance.