How do I put a sales presentation on a page and then make a button appear right when I make the offer sending them to the sales page?

How do I put a sales presentation on a page and then make a button appear right when I make the offer sending them to the sales page? In other words, I have an automated webinar and I make the offer at about 25 minutes in. It is at that precise time that I would like a button to appear below the video.

Put the button in a Section of its own under the video and set the Delay (in Section Settings, the red gear on the right side of the section) to 25 minutes.