/// <reference types="node" />
import { Invoice } from "./invoice";
/**
 * Encodes an invoice object into the bech32 invoice and digitally
 * signs the invoice using ECDSA.
 * @param invoice
 * @param privKey 33-byte secp256k1 private key
 * @returns {string} bech32 encoded invoice
 */
export declare function encode(invoice: Invoice, privKey: Buffer): string;