Thank you. I have downloaded the Telegram desktop application for Linux, but sadly it will not allow me to join without first installing the Telegram App on my mobile phone, which I do not want to do.
Not sure if there is a workaround for this.
Edit: I run Calyxos on my mobile and the Telegram version on the F-Droid store no longer allows account creation, this is now only allowed on the official build. Also, it would appear that the servers run proprietary software, F-Droid warns me that it depends entirely on a non-free network service and the upstream source-code is not entirely free. So I don't think this is the right platform for me.