I just noticed an offer on my Amazon Amex card for 25,000 points if I charge $1500, which expires 12/31/23. Are these points converted into OBC and/or I can use them to pay for a future cruise? Is there an expiration date? In other words, if I pay my September, 2024 cruise with this offer, can I use the points toward another cruise I have in February, 2025?