Hokkaido Shinkansen

I have registered on Hokkaido Rail to reserve tickets on-line. But there doesn't seem to be an option for JR pass reservation i.e. where you don't have to pay for the tickets, but you show your JR pass when you pick them up? I am happy to give them my credit card details to pay the 'fine' if I don't pick up the tickets (like with JR East) but don't understand how to use JR pass in this situation.

The other issue is the train I want to book is Oshamambe to Shin-Hakodate but it doesn't allow pick up of the tickets at Oshamambe?

Another issue is reserving seats on the Hokkaido Shinkansen? I can't seem to get these trains to show up in the clickable map on the Hokkaido booking system.

Thanks!