If you have a custom payload format decoder at TTN (The Things Network), you can send your payload variables directly to TagoIO.
To display locations on a Map, your data needs to be sent inside the "location" field with the format shown below:
TagoIO converts the latitude and longitude fields to the specific format so you don't have to worry about any conversions. In order to accomplish that, you only need to have the variables latitude and longitude or lat and lng, and TagoIO will automatically get these values variables and create a new variable called location.
After you get your device to send the latitude and longitude information to TagoIO, create a dashboard and add a Map widget. Look for the device, and add the variable 'location' inside the map.