How to use:

1. Visit https://accountscenter.instagram.com/info_and_permissions/
2. Export your information > Create export > Export to device
3. Customize information > Make sure Followers and following is selected. The rest can be unselected.
4. Set Date range to All time
5. Set Format to JSON
6. Start export
7. Wait for the export to finish (you'll get an email when it's ready) and download the ZIP archive
8. Extract the ZIP and find the followers_1.json and following.json