https://thenextweb.com/basics/2019/02/06/how-to-unsend-messages-on-facebook-messenger/

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Admit it, we’ve all accidentally sent a meme to our boss, or maybe even an unwarranted ‘hi’ to an ex, and regretted those keystrokes for hours afterwards. Thankfully, Facebook Messenger now allows you to delete a message – both for individual and group chats – for up to 10 minutes after sending it.