how to limit number of slots available

Need help with summer camp registration form - 

Our camp has 6 sessions available. Each session has 5 classes with 15 spots.  Payments will be integrated with PayPal.

I've tried to use the Product widget, but I don't see an option to limit the quantity available. Is there another widget that I should use?  

Unfortunately, the payment fields do not offer a limited quantity option. I see that you have added the Inventory widgets; this is the right way to limit the available quantity. There are also some similar widgets available:

- Appointment Slots

- Ticket Purchases

- Gift Registry

- Quantity Gift Registry

Related guide:

- How to Setup a Payment Order Form with Limited Stocks