Firstly, setup Auto Forward SMS app to forward incoming SMS to a Gmail email address that you own.
- Open Auto Forward SMS app on your phone
- Tap FWD ALL INCOMING SMS button
- Enter gmail email address in the white email address box
Then you need to setup a Telegram Gmail bot to access your Gmail account.
It is a bit fiddly to setup, but you will find instructions on this maketecheasier.com page
There's also info on IFTTT.com . You will need an account with IFTTT to do this.
Let us know if you need a hand.