webln.sendPayment
Request that the user send a payment for an invoice. The application needs to provide a BOLT-11 invoice. Note that WebLN does not yet support invoiceless payments (e.g. Sphinx) so you will need to have a service that dynamically generates invoices per user.
function sendPayment(paymentRequest: string): Promise<SendPaymentResponse>;
interface SendPaymentResponse {
preimage: string;
}