I think it would help to have a more obvious method for dismissing the bubble, like an X button, or a button that explicitly says OK on it, to give a better visual clue for users that are using a touch device or don't think to try hovering over the bubble to see if it's clickable or not.
Hey, good feedback for sure - in all there is no button so as to keep the aesthetic simple - the entire bubble is always the button.
The first step in the tour tells the user they can click to continue, I would definitely recommend that you do this if using the library. You can also hit ESC to exit the tour.