Show button only when the action is available

1. How do I make a button only visible on mobile view?
2. Can we add action in button?

How do I make a button only visible on mobile view?

You need to specify display:none; for it to be trully hidden. In you example you can change the display property of the button to block inside the responsive file and display:none for the text. In the main css file you need to do exactly the opposite.

Can we add action in button?

Put an action button on your slide

On the Insert tab, click Shapes, and then under Action Buttons at the bottom of the menu, click the button shape that you want to add. Click a location on the slide, and then drag to draw the shape for the button.