I accidentally sent my message to the wrong person. How can I undo that?

You can edit a sent message within 24 hours of sending it. This feature is available on the desktop and mobile versions of the website as well as on the VK app for Android and iOS.

You can also delete a message not only for yourself but for everyone in the chat within 24 hours of sending it. To do so, select the message followed by the bin icon. When prompted, select Delete for everyone. Your selection will be remembered for the next time you choose to delete a message. When a message is deleted, replies and forwarded messages aren't removed.
Your search for returned no results.
Try using other keywords, e.g.: "delete profile", "create chat".
Check your request for misprints.