How can I make a macro for rage in Roll20?

So I’m playing using Roll20, and I just took a level in barbarian. I want to save my DM time and set up a macro for rage myself, problem is I have literally not a clue how macros work and the 3.5e character sheet hurts my brain before I even start looking at code. How can I make a macro in Roll20 (unless anyone have a pre-buildt macro by chance)? We use the action bar.