To add friends on Telegram, you have a number of options. It depends how you found the friend, or how they set up their profile. You can add with a phone number, the username, or by viewing the profile and clicking a button to send a request. In any case, it’ll add that user as a friend so you can send direct messages between each other.
The primary way to add friends to Telegram is through the Contacts page. Again, focusing on the Desktop version, click or tap the three horizontal lines at the top of the screen. Then, go to the Contacts page. From there, you can see all your current contacts or add new ones. To add someone new, search their username (if they have one set) or a phone number that they registered with. Their profile will show up, and you can add them from there. This also encourages setting a username for yourself if you don’t already have one. You can do so from the Settings page from the three horizontal lines.
Another way to add someone is if you don’t know their phone number and you met them in a channel or group chat. Click the user to see their profile. From there, you will have the option to add them as a contact. They will receive the request, and once added, you will be able to communicate freely outside that channel.
You can also accept contact requests from the Contacts page as well, so if someone sends you a contact request, you will get a notification. Follow the notification and add your friends. Have fun talking over Telegram!