should i greet him on his bday?

Help! It’s his birthday today and I feel conflicted whether or not I should send a text saying “Happy birthday” and whatnot! We’ve been broken up since March 5th… today also marks the 21st day of no contact. What do you guys think?

UPDATE: Greeted him both through text and FB msg. He said “thank you”. What now? Should I continue NC or start reaching out to him?