You can run your telegram bot on PAW (pythonanywhere) for 0$. If you choose webhook method instead of long pooling, the entire bot can be run as a flask website which is gonna be online for 3 month (Your site can be run indefinitely but to avoid having the site offline, you need to log in to your account and extend it every three months). Copy this sample to your space, place your PAW username and telegram bot API, and finally reload your website. PAW provides SSL for all subdomians so you don't have to buy any certificate.
pip3.6 install --user telepot