When Charges and Credits are placed at enrollment, the Account will have an associated Program when you run a Transactions Report. Payments, however, do not currently work this way. If you want to see how much money you collected for a specific Program, you'll need to use Charges and Credits instead of Payments — here's how.
Calculating Revenue by Program
Run a Transactions Report for a specific date range. See How to Run a Transactions Report for steps (existing link — I'd suggest updating the link text from "Click here" to something descriptive like "How to Run a Transactions Report" for clarity and accessibility, but this wasn't part of your original ask, so let me know if you'd like that change).
Export the report to a CSV file. In the exported file, you'll see a Program column along with a Type column. If the value in Type is Charge or Credit, you'll see a value in Program. If Type is Payment, Program will not be listed.
Sort the spreadsheet by Charges and Credits to calculate your total revenue.
NOTE: This is a known limitation, and we're working on a permanent solution for the future.