How about a subscription to a premium podcast platform like Luminary or Wondery Plus? This will give him access to a wider variety of ad-free podcasts and exclusive content. If he has a particular favorite podcast, you could also get him some merchandise from that podcast such as a t-shirt, mug or keychain. Alternatively, you could create a personalized podcast playlist just for him with all of his favorite podcasts and each episode personally selected by you.
Or you can get him a star map with the date of your anniversary.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.