The modern-day equivalent of the "7-lines of code" is the stripped down, client-side only integration at:

https://stripe.com/docs/payments/checkout/client

tl;dr, click on the stripe website a bunch, then copy and paste the generated html+js (which includes your api key, so you, the user don't have to mess with that) into your own website.

The demo UX is here:

https://70p1h.sse.codesandbox.io/