For some reason, I need to use UE 4.23. I had successfully use your plugin on 5.0 but I could not get it to work on 4.23.
This is my setup:
When I play in the editor, this is the result:
The google sheet URL is already set to anyone with link can view.
I do see a difference in the node between your sample video and my Fill Struct from Google Sheets or Local CSV node. Mine do not have the API Key. I am not sure what else I might be missing.