Webhook using self-signed certificate and Flask (with python-telegram-bot library)

main.py

#!/usr/bin/env python

'''Using Webhook and self-signed certificate'''

# This file is an annotated example of a webhook based bot for
# telegram. It does not do anything useful, other than provide a quick
# template for whipping up a testbot. Basically, fill in the CONFIG
# section and run it.
# Dependencies (use pip to install them):
# - python-telegram-bot: https://github.com/leandrotoledo/python-telegram-bot
# - Flask              : http://flask.pocoo.org/
# Self-signed SSL certificate (make sure 'Common Name' matches your FQDN):
# $ openssl req -new -x509 -nodes -newkey rsa:1024 -keyout server.key -out server.crt -days 3650
# You can test SSL handshake running this script and trying to connect using wget:
# $ wget -O /dev/null https://$HOST:$PORT/

from flask import Flask, request

import telegram

# CONFIG
TOKEN    = ''
HOST     = '' # Same FQDN used when generating SSL Cert
PORT     = 8443
CERT     = 'path/to/ssl/server.crt'
CERT_KEY = 'path/to/ssl/server.key'

bot = telegram.Bot(TOKEN)
app = Flask(__name__)
context = (CERT, CERT_KEY)

@app.route('/')
def hello():
    return 'Hello World!'

@app.route('/' + TOKEN, methods=['POST'])
def webhook():
    update = telegram.update.Update.de_json(request.get_json(force=True))
    bot.sendMessage(chat_id=update.message.chat_id, text='Hello, there')

    return 'OK'


def setWebhook():
    bot.setWebhook(webhook_url='https://%s:%s/%s' % (HOST, PORT, TOKEN),
                   certificate=open(CERT, 'rb'))

if __name__ == '__main__':
    setWebhook()

    app.run(host='0.0.0.0',
            port=PORT,
            ssl_context=context,
            debug=True)

what is the 'path/to/ssl/server.crt' ? please help me.
i write this string and i get erroe

it's path to certificate, look for another path, it seems that you have another one

Been looking everywhere! You're a life saver