To get your tickets, visit Radiant Nature webpage: https://hbg.org/series/radiant-nature/
There is a box labeled “Promo Code” near the top right of the screen once you get to the screen where you select the date you want to attend. RNSWMD23 should be entered in that box, and the user should click the Submit button next to it, before they continue through the ticket buying process. The discount shows up at Checkout.