The process is super simple.
You need two equal-sized files.
The first file is your art.
The second file is a “Depth Map” or “bump map” which tells Facebook which parts of your image should pop forward and which parts should recede. Lighter areas appear closer and darker areas appear further back. This can be as simple or as complicated as you’d like.
The two files need to have similar names with the Depth Map including the suffix “_depth” in its file name. (That underscore is important).
You upload both files to Facebook at the same time and that’s it. Facebook does the rest.
I’ve posted a bunch of tips and tricks and made the layered Photoshop file for this project available to all my patrons on Patreon here: https://www.patreon.com/posts/26710003