Telegram is frustratingly one of those “privacy focused” apps that for some reason feels entitled to have your phone number and requires you to install their app to use. So yes, you need to give it to them. Some feeds have “previews” which can be viewed in the browser, but I’m not sure how common that is.

Also, doesn’t Canada have a king now? Do they still recognise the UK royalty as heads of state, or did that change?