Can't find custom action message

I am running into an issue with a custom action message. I have created the custom action message


I have written the make file which matches the solutions


Finally, I have compiled and sourced but my action message is not found.

This is something I have been running into many times, I am lost to the solution!

** also included is an image of my directory


I had to remove the build folder (rm -rf build) and then repeat the above steps.