UPDATE: I found a solution when I searched on the web. This is the link (cut and paste into browser).
https://www.audible.com/special-promo/2for1/cat

 

Calling all Audible Members:
Did you receive notice of a 2-for-1 Sale? What do you see when you click on the link?

This is what I see:

According to Audible there are more than 180 books in the sale, but I can only get to seven of them. Are you able to see additional books? I have cleared caches, rebooted, cleared history. I have no idea what to do next.