You would include all the ‘includes’ which are currently in the ‘head’ area of that demo into the Head area of your Hype document. You can edit the contents of the … of your exported .html file by clicking on ‘Edit HTML Head’ in the Document Inspector.
You can then use the same code used in the demo to instantiate your virtual keyboard. Just create a rectangle, and add the code for whichever keyboard you’d like in the inner HTML. Edit the Inner HTML of a rectangle by selecting it, and clicking Edit > Edit Inner HTML.