To clear your Telegram history on Android, follow these steps:
1. Open the Telegram app on your Android device.
2. Swipe left on the chat that you want to delete.
3. Tap on the "Delete" button that appears.
4. You will be asked to confirm that you want to delete the chat history. Tap on "Delete" again to confirm.
5. If you want to clear all your Telegram conversations at once, go to Settings > Advanced > Clear history.
6. From there, you can choose to clear all chats, groups, or channels.
Note that clearing your Telegram history will permanently delete all the messages, media, and files from your device, and you will not be able to recover them. Therefore, it's important to make sure that you don't accidentally delete any important data.