Check your inboxes if you already own Project Hail Mary and you're currently subscribed because Audible are giving you a free voucher.
Project Hail Mary is the Audible Editors Extra freebie of the month, so Audible is giving you this voucher to redeem another audiobook of your choice. The voucher must be spent by August 1st.
I got it and used it for "Hitting against the Spin"
Thank you Audible.