Hey, done this in mind for those that have hardware that dont have GPS on the device. We will use the time-stamp method, which means your camera clock will be the same as your gps tracker device (probably your smartphone).
Use a GPS tracker app on your mobile device, this will create a gpx file with the coordinates. These are the ones i recommend:
OSMTracker on Android https://play.google.com/store/apps/details?id=net.osmtracker
Open GPX Tracker for iOS https://itunes.apple.com/pt/app/open-gpx-tracker/id984503772?mt=8
Before starting a sequence (everytime as the camera clock, tends to mismatch if it runs out of battery or a few days without using it), sync the time of the camera the same as your mobile, that can be fixed after on GeoSetter but its less time consuming doing it before recording a sequence. Start recording the track on the app one minute before starting the actual sequence on camera, so the GPS can have better accuracy. Start sequence timelapse on camera. Stop recording on camera when you finished your sequence and after stop recording the track on the GPS tracker app on your mobile device.
Export the gpx file generated on app to your computer (or upload/download on a online storage such as Google Drive. Do the same to the images (in case of 360, stitch them before using GeoSetter).
Install GeoSetter (freeware only for Windows OS, not sure if there’s iOS alternatives) available here https://www.geosetter.de/en/main-en/ Feel free to donate to the author as this software is great and deserves.
Follow the instruction on the video to inject the coordinates into the image EXIF (geotag) using GeoSetter.
Don’t be greedy and try to geotag more than 999 photos at a time, GeoSetter tends to crash if you use more than 999.
Hope it helps, if you guys have doubts, let me know.