You have to have a username to be able to access chat IDs. Telegram doesn’t automatically generate one, so you have to set it yourself. Here’s how: 1. Tap on the Telegram icon on your home screen. 2. In the top-left corner, tap on the three horizontal lines. If the app launched a private conversation when opened, go back to the chat list. 3. Choose Settings from the drop-down panel on the left-hand side. 4. Tap on the Username section under your phone number. Type at least five characters to create a valid username. If it’s available, a notification will appear below. If not, the text will turn red. Telegram will ask you to come up with a different name. 5. Tap on the checkmark in the top-left corner to finish.