Top Level Alpha Light Masking for terrain shadows question

I think I followed JIPS tutorial correctly for creating the correct shadow casting light mask node in World Machine (I also created it right in Gaea) but i think the problem I am having is I am not sure I am saving/exporting this file correctly from Photopea the online photo editor tool. I need specific steps to properly create the alpha channel and get casting just a faint transparent shadow of the mountains onto the ground......I got it working on the top layer but I dont think its correctly applying the transparency as the whole map layer mask looks too dark when I apply it

Which tutorial exactly?
I'd recommend using the Terrain002 shader. An explanation how the texture has to be made to give correct results is available here: https://wiki.faforever.com/en/Development/Mapping