Common to apps using GPS it can take a few seconds or so to get a result. As you tap on a latitude or longitude field the keyboard will appear for the data entry. Taping out of the longitude field for any corner should result in both field backgrounds turning green and the distance from that corner to the user appearing. Again, this may take a few seconds. Pressing the Return key will remove the keyboard. From there the app will display the distance to the corner as the user moves towards or away from the corner. The system seems to be accurate within about 5-10 feet so you will need to look around a little to find any survey marks or geotagged location. Remember you will need to include 4-5 decimal places to achieve this precision. Note 0.0001° latitude is approximately 36 feet (around 37° N). Ref https://www.nhc.noaa.gov/gccalc.shtml with the best accuracy (open sky and multiple satellites) as about 16 feet (https://www.gps.gov/systems/gps/performance/accuracy/). e&oe.
MapKit with UIViewRepresentable
LocationManager to find the User
@EnvironObject to allow 'global' variables