If you run your Telegram bot locally, it will stop working when you close the terminal. The alternative is to host the bot somewhere.
There are many ways to do this. I chose AWS EC2 as it's a cheap and easy option.
Create an AWS account and start an EC2 instance. Install pip, git and github cli. If you use an Amazon Linux image (which is what the free tier offers) you can run the commands in this gist.
Connect to your GitHub account with gh auth login
and clone this repo. Create the .env