Telegraf and Heroku not sending the first reply on webhook [nodejs] - node.js

Question

I am tring to write a simple bot that after some task reply with a text.
The bot offline with app.polling is working perfectly. But when I deploy it on heroku, if I write only one ctx.reply(), no message is sent. If I write it twice, one message is sent on telegram. You can see the code on the snippet below, I included only the necessary code (the log show me with console.log that all the function are working and the final text is ready to be sent, I also commented the code a little to exlpain better the situation).
So this appear strange to me,can anyone explain why?
const Telegraf = require('telegraf');
const request = require('request');
const date = require('date-and-time');
const API_TOKEN = process.env.API_TOKEN || ''; //the api token is into env var
const PORT = process.env.PORT || 3000;
const URL = process.env.URL || 'url of my heroku account';
const app = new Telegraf(API_TOKEN);
app.telegram.setWebhook(`${URL}/bot${API_TOKEN}`);
app.startWebhook(`/bot${API_TOKEN}`, null, PORT);
function getdata(ctx,stazione1,stazione2){
let tempo = gettempo();
let linkget = '....';
var options = {
url: linkget,
headers: {
'Referer':'http://m.trenord.it/site-lite/index.html',
'secret': '...'
}
};
let linkget1 = '...';
var options1 = {
url: linkget1,
headers: {
'Referer':'...',
'secret': '...'
}
};
request(options, function(error, response, body){
request(options1, async function(error1, response1, body1){
let text = await gettext(body,stazione1,stazione2);//return text
let text1 = await gettext(body1,stazione2,stazione1);//return text
let final = await text+"\r\n\r\n"+text1;
console.log(ctx);
//here is the problem, if i write only one reply no message is sent on the bot, but if i wrtite it twice one message is sent.
ctx.replyWithMarkdown(final);
ctx.replyWithMarkdown(final);
});
});
}//getdata
app.command('pl', function(ctx){
getdata(ctx,stazione1,stazione2);
});
NEWS
I want to add some feedback while the server works, so I add a ctx.reply("searching...") after the command right before the function getdata is launched. Now all two messages are sent to telegram. On the previous case is possible that heroku "shut down the webhook" and at the first ctx.reply was wake up and than at the second ctx.reply the message was sent?

Answer 1

I'm using node-telegram-bot-api for node.js/Heroku and this config work well for me:
const options = {
webHook: {
// Port to which you should bind is assigned to $PORT variable
// See: https://devcenter.heroku.com/articles/dynos#local-environment-variables
port: process.env.PORT,
// you do NOT need to set up certificates since Heroku provides
// the SSL certs already (https://<app-name>.herokuapp.com)
// Also no need to pass IP because on Heroku you need to bind to 0.0.0.0
},
};
// okk
// Heroku routes from port :443 to $PORT
// Add URL of your app to env variable or enable Dyno Metadata
// to get this automatically
// See: https://devcenter.heroku.com/articles/dyno-metadata
const url = process.env.APP_URL || 'https://my-bot.herokuapp.com:443';
const bot = new Tg(config.BOT_TOKEN, options);
// This informs the Telegram servers of the new webhook.
// Note: we do not need to pass in the cert, as it already provided
bot.setWebHook(`${url}/bot${config.BOT_TOKEN}`);