The steps below will help you to recover deleted Telegram messages, regardless of whether you deleted them mistakenly or intentionally:
1. First, login to you telegram account and then click on the setting button
2. After then click on the “advance” button, then choose “Export Telegram Data” option and then select types of chat you want to export.
3. After then, choose the HTML format, and finally click on the Export button.
Read more: https://ityug247.com/recover-deleted-telegram-messages/