Find out what people actually ask
Before writing any automation in your Telegram bot, read a month of your own messages and count. Most sellers find four or five questions covering the bulk of them, and are surprised by which one is first.
Automating a question nobody asks is work that helps nobody.
Answer in the product description first
If three people ask the same thing about one item, the item's description is missing a sentence. Fixing it there removes the question for everyone who comes after, including the ones who would not have asked and just left.
Then set up the repeatable answers
Auto-responses and triggers in Telegram reply when a message matches, and a conversation flow can walk someone through a longer answer. Write them the way you would say it, not the way a form would.
Say what the bot cannot do
An automated answer that pretends to be you is worse than no answer. Make it clear a person will follow up for anything unusual, and then actually follow up.
Keep the hard questions coming to you
Anything about a specific order, a complaint or an exception should reach a human. The job of the Telegram bot is to clear the easy traffic so the hard messages are visible, not to make all traffic disappear.
Check what it is doing
Read the replies the bot sent once a week for the first month. An auto-answer that fires on the wrong phrase is embarrassing in a way you only find by looking. The modules are listed on Modules; the FAQ on FAQ covers how the pieces fit together.