yarn install
yarn dev
This starts a public live session of Netlify Dev. More info.
https://api.telegram.org/bot{your-bot-api-token}/setWebhook?url={netlify-live-url}/.netlify/functions/bot
Go to above url in your browser and replace the token and the url. This tells the bot to call your dev instance instead of the live one.
git push
to this repo starts the build process on Netlify. After that you need to set the webhook again to point to the production url.