I can possibly make it so that the flipbook page opens in a new tab such that when they close it the confirm page is still open (just like using the back button on the flipbook page), or perhaps even go to a different page of your preferred choice, personally I really am very cautious about messing with their code, in-fact cautions is the mild way to put it, and it could even open up some issues with intellectual copyright, unless of course they have agreed that you can mess about with their code.

I understand. Thank you so much for your help and explanation! I am ready to move forward with what you have—agreed that I do not want to mess with their code.
You are a superhero, Wayan!

So would you like either a step by step video showing how to, or written instructions?

I would have to make the Step By Step video later today, as it is 2:00 AM here and we live in a very remote area of rural East Java, it's very quiet here (apart from the mooing of hungry cows, the cockerels crowing, the frogs calling for some mating fun,) and the occasional thunder clap, signalling the start of the dry season), you can here a pin drop from 1000 meters away. I am up and around but my family are still in the land of nod.

I can write some instructions to set it all up, but perhaps a video would be better. Up to you though

Thank you. Writing will be great!!