i usually do something small with some friends! i also do a party with my extended family at my grandma's house.
i've never liked a ton of attention on my birthday! i generally don't want people to know about my birthday unless i tell them myself, and teachers in school or waiters at restaurants singing happy birthday didn't go by that rule. i'm a lot more comfortable celebrating my birthday online, though, because a messages in a discord server or a forum is a lot less overwhelming for me.
during my last year of high school, a lot of people in my classes would sing the usamerican national anthem to each other on their birthdays. they didn't know about my birthday [and probably didn't care about me anyway], but the possibility of being patriotically serenaded was the only time i kind of secretly wanted a more public celebration.