I'll probably just go out for dinner with my husband. Usually I have a party with friends and family as well, but this year that isn't a good idea. Just when I'm turning 65, too... :(
Personnaly I don't. I just call some friends individually and organize a serie of 1-1 dinners.
The science youtuber behind the channel "the thought emporium" and "the taste emporium" has an interesting take on this : https://www.youtube.com/watch?v=8djjv5ovMNo at 25 seconds. Basically he makes a cake outside of his skill set, spends the whole day on it and give it to his friends.
Or: what's a cool idea to celebrate your birthday?
Or: why don't you celebrate your birthday?