1) TLDR lessons;
1 minute impression
I found the DIY version too long… It will take an average user around 10–15 minutes to create a Telegram bot and host the alerter on Heroku.
With the goal for users to receive alerts immediately, I created a Telegram bot (@caroualert_bot) and integrate it to the Cron job below. They can add items to monitor and @caroualerter_bot will send the updates.