Generating and accessing order codes

I don't currently have a SquareSpace site and am shopping around for a service that provides the functionality I need. 

Specifically, I have a non-SquareSpace website that runs a script. This script is quite expensive to run computationally so I'd like people to have to pay to run it.

I would like a storefront that:

1. Lets people purchase a "script-running code" (which could just be any sort of reasonably-difficult-to-guess order code)
2. So they can paste their code into my other website.
3. Then, my website verifies that the code has been paid for and not used yet, and then runs the script.

So what I'm curious about with SquareSpace is:

1. Is it possible (or, even better, the default) to create a SquareSpace store item that is basically an order code randomly-generated upon purchase?
2. Can I access the confirmed order from my script (or even just have SquareSpace send an order email to me so I can have the script check the email)?

For #2 I know SquareSpace has an API for orders but it requires the highest-tier plan. I'm not running at very big scale here so a little kludginess is okay.

Thank you!