To delete a channel with over 1,000 subscribers, you need to contact user support The optimal dimension of the avatar on Telegram is 512px by 512px, and it’s recommended to use PNG format to deliver an unpixelated avatar. Telegram desktop app: In the upper left corner, click the Menu icon (the one with three lines). Select “New Channel” from the drop-down menu. More>> Each account can create up to 10 public channels
from us