How Can I Limit the Quantity Sold?

I am using JotForm for an online box office for our theater department. I have a couple questions:

1. How can I limit the quantity sold for each product?

2. Can I have it say sold out when the all the tickets have been sold? 

3.

1. Unfortunately, it is not possible to add limit of quantity for Stripe widget or any widget under Payments tab. But, you can use Gift Registry instead and pass the total value into your payment widget using calculation.

Here is the guide on how to pass calculation to payment field. https://www.jotform.com/help/275-How-to-Pass-a-Calculation-to-a-Payment-Field

2. Gift Registry has this feature.

I have cloned your form and provided an example using the Gift Registry widget.

https://form.jotformpro.com/72534575919973 - You may clone this to check what I did.

How to clone : https://www.jotform.com/help/42-How-to-Clone-an-Existing-Form-from-a-URL