[rickitan]

I recommend Shopify's Checkout

Disclaimer: I work for Shopify (But I also use it for my side hustles)

The biggest benefit is that with the Shopify checkout you can support credit cards, Paypal, Apple Pay, Google Pay, Crypto and more with ONE integration.

You also get discounts codes and logic out of the box (buy one get one, X percentage off, fixed amount off, etc)

And all you have to do is listen to the order completion web hook and do whatever you want on your side.

You can use the JavaScript SDK to send your users to the checkout. https://shopify.github.io/js-buy-sdk/

Hope that helps!