TPE is primarily a planning tool intended to check light direction for a date and place other than here and now.
However, if you do want to check "here", then you can:
Once enabled, track current location looks like this:
If you press the button a second time, you can also have the map track your device's current heading:
Still having trouble?
Check TPE's permissions under Android Settings > Apps. Ensure that the app has permission to access your device's location.