Here are the steps to extract the DJI flight log file and convert it to a .GPX for GeoSetter.
Typically you will need to delete all the columns in the resulting CSV except for the ones titled Longitude, Latitude, and relativeHeight. Unfortunately it does not look like any time (local, UTC, GPS, etc) is saved in the log file, as DJI likely bases it on the app's local time and only saves an offset. This means that in the video guide below, you will need to match up the image to the waypoint location, and not look at the time offsets (since the waypoints will not have a time value saved).
Step 3: On gpsvisualizer.com change output format to GPX. Click the "Choose File" button to load your csv. Click "Convert" button. On page that opens, right click on the "following link" text and choose "Save link as..." to save the converted GPX.
Step 4: Follow the below video tutorial (starting at minute 4:06) about geo-tagging in GeoSetter using the GPX file.