You just need the app. Either the older version (no account needed) or the new app (with an account).

But this also depends on the camera. I believe new ones can geotag live via Bluetooth (with the app). This is how my Panasonic camera does it.

But you can also set the app to keep a log of your location, so as you take photos, you can have the app tag them before transfer.

Check your camera’s manual to see how it works.