If you have made the switch to charge upfront, you will no longer be able to switch to per creation.
Before switching the payment type on your account, make sure to communicate the change to your patrons! Once you've shared the news of the switch with them, here is how to change your payment type for your account:
Step 1: From your creator page, navigate to the top of your creator page and click edit your page.
Step 2: In your page editor, click the payments tab from the upper menu where you can toggle between monthly, or per creation. Don't forget to save your changes before you exit the page!
If you're switching to "per creation," enter what it is that potential patrons will be paying for when they become your patron (i.e. per video, per episode). If you're switching to "monthly," you will not need to enter what it is you create.