Unlike Signal and WhatsApp, Telegram didn't offer a dedicated disappearing messages mode until now. Telegram Desktop 2.6 lets you set messages to auto-delete for everyone 24 hours or 7 days after they've been sent, and the best thing is that the feature works on any chat, as well as in groups and channels where you're an admin. To use the new disappearing messages feature in chats or groups, you'll have to right click on the respective chat in the chat list where you want to enable auto-delete, go to Clear History, and then click on Enable Auto-Delete. Only in chats, you can also enable auto-delete by clicking on Clear History on the right side pane.
Unlike Signal and WhatsApp, Telegram didn't offer a dedicated disappearing messages mode until now.