Need help ...having problem with control overlay.js

Iam trying to implement joystick controls over my game: warzone11.herokuapp.com

but Iam not able not to understand how to add those buttons and joystick ….i need to know what part of the code from cocoapp.js need to be inserted into a simple game our just on a simple canvas ….i have read the whole documentation but found no good solution for that …

I also tried to remove that black (by default background ) but it just didn’t removed ……any one plz help me out ….