The workflow listens for messages sent to your Telegram bot. The first word is read as a command. /add saves the rest of the message as a new open task, /list replies with all tasks that are not done, and /done marks the task whose text matches as done.

Each task is stored as a row in a Google Sheet with its status and the chat it came from. The bot confirms every change in the same chat, so you can keep the list in one place without opening the sheet.