Here is the page that will explain what your options are. Please note that it is set to the annual rate but you can change it to the monthly rate if you want and you feel that is better for you.
In my experience, I find that knowing that it is always there especially when you begin to rely on it is very satisfying. For example, writing ads with the correct personalisation is a real boon and a magnificent time saver. It’s accuracy is astounding and it comes with a whole suit of training.