How to get tickets to the Ellen show?

I went online to her website and saw the calendar. However, all that I
saw was months May  April filled with "No Tickets Available" in red.
The rest of the months were all grayed out; I tried to click on them
but it didn't take me to those months. Then how are you supposed book
the tickets then???

If there're some tickets available what will you see? Anybody here has
tried and succeeded can you give me a detail walk-through since I'm
very confused.