Having received an Overlander yesterday I can see the need for a separate section here for help. Although it does not have inReach built in it has the ability to connect to inReach devices.
More's the shame. According to the manual "The Garmin Explore website and mobile app allow you to plan trips and use cloud storage for your waypoints, routes, and tracks." So going to explore.garmin.com leads to https://explore.garmin.com/Account/GarminUser > "I have one" > "Don't have a smartphone? Set up your device on your computer with Garmin Express." Oh dear, oh dear.