Thank you, but that’s not actual plugin I need. I used that tutorial, only to learn how to add new plugins.
one that I actually need is this one:
VaRest allows us to make http requests from blueprint.
But I had same problem with VaRest: “Plugin ‘VaRest’ failed to load…”.
And it’s a bit surprising to me that a plugin needs two separate versions for mac and windows (I didn’t knew that, sorry), because I once transferred an entire UE4 project from mac to windows and it worked without any change whatsoever. So I figured if a project works, of course module works. 
Thanks again for your reply.