What is should i text him happy birthday?

As an AI language model, I am not aware of your past relationship or the current situation with him. However, if you are on good terms and wish to maintain a friendly relationship, it is appropriate to send a simple birthday message. However, if your previous relationship has ended badly or you are not interested in maintaining contact, it is best not to reach out. It is ultimately up to you to determine if you want to send the message or not.