If you want to Develop photos in Lightroom Classic to share to Instagram with a carousel format, follow these steps:

  1. In Lightroom Classic, choose a photo.
  2. Crop the photo in 16 x 10.
  3. Right click on the photo and click “Edit in Photoshop.”
  4. In Photoshop, hold down on the Crop tool and select the Slice tool.
  5. Create two slices using the slice tool.
  6. Then go to File > Export > Save for Web.
  7. In the Image Size section, change the height to 1350 and the width to 2160.
  8. Choose either slice and change the format to JPEG then set quality to 100.
  9. Do the same to the other slice.
  10. Click save, be sure that “All slices” is ticked, and choose the location for your new file.

You can follow a similar process to Develop a two-slice landscape photo with a border for an Instagram carousel post.

References

Dunna Did It. (2019, February 25). How To Split Pictures For Instagram // Seamless Multi-Post Tutorial. https://www.youtube.com/watch?v=cgKcF8mw2Z4