Twilio Flex Function to route calls to a Voicemail TwiML on TaskRouter Workflow timeout

timeout.js

const VOICEMAIL_TWIML_URL = 'https://handler.twilio.com/twiml/XXXXXXXXXXXXXXXXXXXXXXXXXXXX';

process.on('unhandledRejection', error => {
    console.log('unhandledRejection', error.message);
});

exports.handler = function (context, event, callback) {

    var twiml = new Twilio.twiml.VoiceResponse();
    const client = context.getTwilioClient();

    if (event.DialCallStatus === "completed") {

        twiml.hangup();
        callback(null, twiml);

    } else if (event.EventType == "reservation.timeout" || event.EventType == "workflow.timeout") {

        console.log(event.EventType);
        console.log('timeout');
        const attributes = JSON.parse(event.TaskAttributes);

        client.calls(attributes.call_sid)
            .update({ method: 'POST', url: VOICEMAIL_TWIML_URL })
            .then(call => {
                console.log(call.to)
                callback(null, twiml);
            })
            .catch(error => callback(error));
    } else {
        callback(null, twiml);
    }

};