Subscribe to invoices using EXPRESS + SERVERLESS (Lambda)

subscriptions.ts

import LndService from "./services/LndService";
import paymentsService from "./services/paymentsService";
const { subscribeToInvoices } = require("ln-service");
const lnService = require('ln-service');
class Subscriptions {

  public initWS = async () => {
 
    // Since BTCPay Server closes WS every 90 seconds it must be looped
    try {
      const {lnd}= lnService.authenticatedLndGrpc({
          socket: LndService.getNodeAddress(),
          macaroon: process.env.LND_MACAROON
          // cert: NOT NEEDED AS WORKING UNDER BTCPAY SERVER GRPC SUITES
      });
      let websocket : any;

      websocket = subscribeToInvoices({lnd})

      websocket.on('error', async err => {
        // recursive call to reconnec on error as BTCPAY closes sockets connection every 90 secs
        try {
          await this.initWS()
        } catch (err) {
          console.log(err)
        }
      })

      websocket.on("invoice_updated", async (data: any) => {
        console.log("Subscribed")
        // If invoice is paid
        if (data.is_confirmed) {
          try {
            const invoiceData = await paymentsService.getPaymentForViews(
              data.id
            );
            if (invoiceData.Count && invoiceData.Items) {
              const invoice = invoiceData[0];
              await paymentsService.payInvoice(
                invoice.invoiceId,
                invoice.keyId
              );
              console.log("Invoice paid: " + invoice.invoiceId);
            }
          } catch (error) {
            console.error(
              new Date().toLocaleString() +": " + error
            );
          }
        }
      });
    } catch (error) {
      console.error(new Date().toLocaleString() + ": " + error);
    }
  };
}

export default new Subscriptions();