IconVault's Payment Handler Playground teaches the PaymentRequest API by letting you run it. Construct a genuine PaymentRequest with basic-card or a custom method identifier, set a total and currency, then call canMakePayment() against your own browser and watch the result in a timestamped session log. A step-through simulator then walks you through show(), the payment handler invocation, and complete('success'). It is free and runs fully in your browser.

The PaymentRequest API is how the web replaces clunky checkout forms with the browser's native payment sheet. This lab makes the flow concrete: you see the method data, the line items, and the exact order of operations, plus honest notes about what a real charge requires (an installed payment handler, HTTPS, and merchant credentials) so you never confuse the sandbox with production. Export the session log and take the pattern back to your own code.