Following the steps from this article to add a Tour, this article will show you how to setup a GPS Coordinate as a checkpoint in a Tour. This will act like a typical checkpoint when the officer enters the specified area with their device.
Add a "Tag"
In the Tags portion of the Tour Details, click on the Add button. Then, enable the GPS Triggered checkpoint setting. You will be given two more options to configure: Reading Perimeter, and Tag Location. The Reading perimeter is the size of this checkpoint, changing this will show you a approximate size of the circle on the map. To change the location of the checkpoint on the map, you can enter an address or right-click on the map to drop a pin.
Make sure you also give this checkpoint a Tag Name as well, and click Add to save this checkpoint.