Software license activation

I am just dipping my toe into Shopify app development.

I have some Rails experience.

My use case is: interfacing to an existing software licensing API.
Essentially, when a user makes a purchase of a given software product, I want to make an API call to generate a license key, and then I want to email that to the user. Ideally I’d like to store it in the user’s account too.

I assume that this is a “Fulfilment” app.

I followed the tutorials using Remix, and then realised I can also build it with Rails, which I think I’d prefer.

Any tips and recommendations would be much appreciated!

Looks like I just need the order paid webhook to achieve this.