ok, he has Skies of Terra and heart of the matter
I have rendered a backdrop here using them
he loads the preload and delete all but the ground and the HDMtree
leaving the stuff below in the scene tree
then puts my image in backdrop, not background
he the consolidates duplicate shaders leaving only 3
and oops, I just see my final image did not upload with text showing to choose each of those shaders and go to lighting shadowcatch in the texture room!
I will upload it later, not on computer now.