If you would like to bill the same amount every month, then the billing from your calendar is not going to be the most ideal feature for you to use. In that case, it would be easier to simply create a recurring invoice. (Add a monthly fee to the line item, then at the bottom of the invoice, you can set it to repeat every month.) In this way, it will be automatic.
To clarify, “Automatic Billing from Calendar” is only for people who want to charge different amounts each month based on how many lessons are showing on the calendar. We hope this helps, and feel free to connect with us for any other inquiries