Link
I am not a Premium Plus member but I can actually see the sale titles (for a change). Hope that link works for actual Premium+ members and that you find titles that you like in the sale!
T&C
*Sale ends June 10, 2022 at 11:59 PM PT (US). Offer is available only for active Audible US Premium Plus members (gift memberships and Silver plans included). Only credit purchases are eligible for this sale. Offer is not available from within the Audible app. To redeem this offer, add two audiobooks to the cart from the selection provided. When you check out, you will be able to purchase both audiobooks for one credit - either by using a credit you have, or by purchasing one at the time of check out. Offer is not transferable and cannot be combined with any other offer. Audible reserves the right to cancel the offer at any time. If you violate any of these terms, the offer will be invalid.