Keep users on the last page they visited in a prototype

I have a prototype that’s designed so that users can only follow a specific path out of multiple possible paths/flows. It’s really important that users can’t go back to the beginning, or all of their progress will be lost.

So, is there a way to make the prototype stay on the last page the user was on? How do I stop the prototype from going back to the beginning of the flow when it’s refreshed?