First, you'll need to create a new form. Here's how to create a new form.
Next, hover your cursor over the new Payment Options form and click Edit Form Fields —> Inside the form, click Add Field to Form —> more options will appear on the left side panel, scroll down and open the Payments and Orders category —> hover over Autobilling Options and add to the bottom of the form —> click Save Form to save your changes.
The Autobilling Options field shows the autobill plans in the project. Here's how to create an autobill plan