If you have a program that should be charged on a recurring basis, create a program with a one-time fee that is equal to one installment amount.
For example, if students can enroll in Lunch and it costs $100/month, create a Monthly Lunch program with a $100 one-time fee.
Make sure the program is checked off in the Add-Ons section of your listing. When accepting a student to the program, by dragging and dropping from the Applied to the Accepted column, the program enrollment will be listed in the Items section. Click the gray edit icon to edit the program enrollment. Edit the frequency of the charge from "Paid all at once" to "Recurring for a set amount of time". Select the frequency and duration you'd like the program to charges to reoccur for. Save the item and continue to accept the student.