Procedure on Telegram for channel creation
1. On the Conversation list tap/click on the button that allows you to open a new chat (it is different depending on the devices and on the OS)
2. Choose "Add channel".
3. Then fill every fields with your information and be sure to make the channel "public".
At the end of the page you can see a field which contains "t.me/link" where you have to replace "link" with your channel name (this will be an information that you will have to add in the CMS)