Firebase Auth + Stripe Checkout + Gatsby

Hey IndieHackers! I'm working on an online video course. I'm building it with Gatsby and hosting on Netlify. So far I've learned that I can use Stripe checkout to take payments on the landing page which looks easy enough to setup.

Also setting up a backend with Firebase is doable in Gatsby and looks pretty easy to setup as well.

I've finished building the landing page so now I'm planning on how to create users with their emails after their payment in Stripe has gone through.

I found this thread here: https://www.indiehackers.com/forum/firebase-stripe-subscription-integration-help-needed-9312a80db1

Which lead me to this repo: https://github.com/firebase/functions-samples/tree/master/stripe

Does anyone have any examples or a little direction on how to set this up?