<form method="POST" action="https://btcpay264939.lndyn.com/apps/ueTNEqt56LWgCqsdYrY64gpiwx1/pos"> <input type="hidden" name="email" value="customer@example.com" /> <input type="hidden" name="orderId" value="CustomOrderId" /> <input type="hidden" name="notificationUrl" value="https://example.com/callbacks" /> <input type="hidden" name="redirectUrl" value="https://example.com/thanksyou" /> <button type="submit" name="choiceKey" value="liftime">Buy now</button> </form>