fulfillment code error Webhook call failed. Error: UNAVAILABLE - dialogflow-es

Question

I am developing a voice assistant through dialogflow, google calendar and voximplant.
I have a problem in the fulfillment code because, I don't know why, but I constantly get this error in the DIAGNOSTIC INFO, as well as a series of errors on the console log. Would anyone know how to give me a hand?
I will post the code below:
// See https://github.com/dialogflow/dialogflow-fulfillment-nodejs
// for Dialogflow fulfillment library docs, samples, and to report issues
'use strict';
const functions = require('firebase-functions');
const {google} = require('googleapis');
const {WebhookClient} = require('dialogflow-fulfillment');
// Enter your calendar ID below and service account JSON below
const calendarId = 'c_d86ppgn4qqpmfpq1cjd2higja8#group.calendar.google.com';
const serviceAccount = {
"type": "service_account",
"project_id": "italians-do-it-better",
"private_key_id": "xxxxxxxxxxxx",
"private_key": "-----BEGIN PRIVATE KEY-----\nxxxxxxxxxx\n-----END PRIVATE KEY-----\n",
"client_email": "xxxxxxxxxx#italians-do-it-better.iam.gserviceaccount.com",
"client_id": "xxxxxxxxxxx",
"auth_uri": "https://accounts.google.com/o/oauth2/auth",
"token_uri": "https://oauth2.googleapis.com/token",
"auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
"client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/appointmentscheduler%40italians-do-it-better.iam.gserviceaccount.com"
};
const serviceAccountAuth = new google.auth.JWT({
email: serviceAccount.client_email,
key: serviceAccount.private_key,
scopes: 'https://www.googleapis.com/auth/calendar'
});
const calendar = google.calendar('v3');
process.env.DEBUG = 'dialogflow:*'; // enables lib debugging statements
const timeZone = 'Europe/Kaliningrad';
const timeZoneOffset = '+02:00';
exports.dialogflowFirebaseFulfillment = functions.https.onRequest((request, response) => {
const agent = new WebhookClient({request, response});
console.log("Parameters", agent.parameters);
const appointment_type = "Default";
//agent.parameters.AppointmentType;
function makeAppointment (agent) {
// Calculate appointment start and end datetimes (end = +1hr from start)
console.log("Parameters", agent.parameters.date);
//Variabili più calcolo orario
const guests = agent.parameters.guests;
const dateTimeStart = new Date(Date.parse(agent.parameters.date.split('T')[0] + 'T' + agent.parameters.time.split('T')[1].split('+')[0] + timeZoneOffset));
const dateTimeEnd = new Date(new Date(dateTimeStart).setHours(dateTimeStart.getHours() + 1));
console.log("date start ", dateTimeStart, " date end ", dateTimeEnd);
const date = new Date(agent.parameters.date);
const bookingDate = new Date(date);
const phonenumber = agent.parameters.phonenumber;
let name = agent.parameters.name;
const email = agent.parameters.email;
var phone = phonenumber.toString().length;
const now = new Date();
const appointmentTimeString = dateTimeStart.toLocaleString( 'en-US', {timeZone:'Europe/Kaliningrad'});
if (guests < 1){
agent.add(`You need to reserve a table for at least one person. Please try remaking the reservation!`);
}
else if (guests > 100){
agent.add(`You can't make a reservation for more than 100 guests. Please try remaking the reservation!`);
}else if (dateTimeStart < now){
agent.add(`You can't make a reservation in the past. Please try remaking the reservation.`);
}
else if (bookingDate.getFullYear() > now.getFullYear()) {
agent.add(`You can't make a reservation for ${bookingDate.getFullYear()} yet. Please choose a date in ${now.getFullYear()}.`);
}
else if (phone != 10) {
agent.add(`Your phone number has to be atleast 10 digits. Please try remaking the reservation!`);
} else {
console.log("appointmentTimeString: ", appointmentTimeString);
// Check the availibility of the time, and make an appointment if there is time on the calendar
return createCalendarEvent(dateTimeStart, dateTimeEnd, guests, name, phonenumber, email, appointment_type).then(() => {
agent.add(`Ok, let me see if we can fit you in. ${appointmentTimeString} is fine!.`);
}).catch(() => {
agent.add(`I'm sorry, there are no slots available for ${appointmentTimeString}.`);
});
}
let intentMap = new Map();
intentMap.set('collectIncorrectValues', makeAppointment);
intentMap.set('ScheduleAppointment.yes', makeAppointment);
agent.handleRequest(intentMap);
}});
function createCalendarEvent (dateTimeStart, dateTimeEnd, guests, name, phonenumber, email, appointment_type) {
const appointmentTimeString = dateTimeStart.toLocaleString( 'en-US', {timeZone:'Europe/Kaliningrad'});
return new Promise((resolve, reject) => {
calendar.events.list({
auth: serviceAccountAuth, // List events for time period
calendarId: calendarId,
timeMin: dateTimeStart.toISOString(),
timeMax: dateTimeEnd.toISOString()
}, (err, calendarResponse) => {
// Check if there is a event already on the Calendar
if (err || calendarResponse.data.items.length > 0) {
reject(err || new Error('Requested time conflicts with another appointment'));
} else {
// Create event for the requested time period
calendar.events.insert({ auth: serviceAccountAuth,
calendarId: calendarId,
resource: {summary: 'Appointment: '+ appointment_type +' Appointment ', description: appointmentTimeString +',\n Name: ' + name + ',\n Guests: '+ guests + ',\n Phonenumber: ' + phonenumber + ',\n Email: ' +email,
start: {dateTime: dateTimeStart},
end: {dateTime: dateTimeEnd}}
}, (err, event) => {
err ? reject(err) : resolve(event);
}
);
}
});
});
}
package.json:
{
"name": "dialogflowFirebaseFulfillment",
"description": "This is the default fulfillment for a Dialogflow agents using Cloud Functions for Firebase",
"version": "0.0.1",
"private": true,
"license": "Apache Version 2.0",
"author": "Google Inc.",
"engines": {
"node": "10"
},
"scripts": {
"start": "firebase serve --only functions:dialogflowFirebaseFulfillment",
"deploy": "firebase deploy --only functions:dialogflowFirebaseFulfillment"
},
"dependencies": {
"actions-on-google": "^2.2.0",
"firebase-admin": "^5.13.1",
"firebase-functions": "^2.0.2",
"dialogflow": "^0.6.0",
"dialogflow-fulfillment": "^0.5.0"
}
}
Console log error:
Dialogflow error:
Console log error:
{
"textPayload": "Error: No handler for requested intent\n at WebhookClient.handleRequest (/workspace/node_modules/dialogflow-fulfillment/src/dialogflow-fulfillment.js:317:29)\n at exports.dialogflowFirebaseFulfillment.functions.https.onRequest (/workspace/index.js:89:10)\n at cloudFunction (/workspace/node_modules/firebase-functions/lib/providers/https.js:57:9)\n at process.nextTick (/layers/google.nodejs.functions-framework/functions-framework/node_modules/#google-cloud/functions-framework/build/src/invoker.js:100:17)\n at process._tickCallback (internal/process/next_tick.js:61:11)",
"insertId": "000000-9adc6f24-bfa5-469b-ae82-5f4124522534",
"resource": {
"type": "cloud_function",
"labels": {
"function_name": "dialogflowFirebaseFulfillment",
"region": "us-central1",
"project_id": "italians-do-it-better"
}
},
"timestamp": "2021-07-13T08:31:30.209Z",
"severity": "ERROR",
"labels": {
"execution_id": "v9ps952et2kk"
},
"logName": "projects/italians-do-it-better/logs/cloudfunctions.googleapis.com%2Fcloud-functions",
"trace": "projects/italians-do-it-better/traces/f4d789b9c84aaf5bb311c9332f125ca8",
"receiveTimestamp": "2021-07-13T08:31:30.716907289Z"
}