Communication between html and ue4html5

I am having an hard time finding correct information on how to setup interaction between ex. html-button and ue4-html-canvas/ue4 engine.
Reading documentation,forums and answerhub regarding this subject is a maze and with incomplete solutions.
Could anyone PLEASE give a working example guide that is complete with header,cpp,js and html?.
btw, no rest api plugins work when packaging to html5.

Down below, other people that went trough the same problem…

https://forums.unrealengine.com/development-discussion/html5-development/1630692-call-c-functions-from-js

I consider this problem solved, read here for solution: Is it possible to include HTML5 JS files from the project or plugin? - Platform & Builds - Epic Developer Community Forums