I meet the same issue.
I already clicked the "own Fences 2.0?" and I got "Great, you qualify for a Fences upgrade. Please select a product and proceed to checkout.Try a different email"
But I don't know how to continue.
I don't know where can I select a product.
I also has a ticket for this issue: https://esupport.stardock.com/index.php?/Tickets/Ticket/View/844529