Why node js telegram bot placed on heroku answer with 403

I write telegram bot and use Telegraf library. I placed my bot on Heroku. I set up webhooks this way:

app.telegram.setWebhook(`${URL}/bot${BOT_TOKEN}`);
app.startWebhook(`/bot${BOT_TOKEN}`, null, PORT);

But in Heroku logs I see at=info method=POST path="/bot" host=my-app.herokuapp.com request_id=a8f99998-5e9b-4fe4-9af6-9ac56e492ae3 fwd="149.154.167.206" dyno=web.1 connect=3ms service=4ms status=403 bytes=101 protocol=https

getWebhookInfo() also log last_error_message: 'Wrong response from the webhook: 403 Forbidden Trying test example from telegram webhook guide with postman also return 403

via Adara Hv