Manually-created entity: not available for map?

I have an LTE modem mounted in a vehicle that sends its coordinates to HA every 30 seconds via API call. I can see the Entity (called Vehicle.gpstest) in the entities list, however I cannot add to the map.

I’m assuming the problem is either the attributes aren’t correctly configured, or I have to manually add a device/platform into HA for it to know its a GPS device.

What do I have to do to get this entity in the map with its coordinates?

Add latitude and longitude as attributes
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