Request that the user sends a payment for an invoice. The application needs to provide a BOLT-11 invoice
async function sendPayment(paymentRequest: string): SendPaymentResponse
interface SendPaymentResponse {
preimage: string;
}
const provider = (window.$onekey && window.$onekey.webln) || window.webln;
const invoice = "lnbc100xxxx";
await provider.enable();
const info = await provider.sendPayment(invoice);