In the Messages app, you can edit or unsend a message.
You can edit a recently sent message up to five times within 15 minutes of sending it.
Go to the Messages app on your Apple Watch.
Touch and hold the message bubble, then tap Undo Send.
A note confirming that you unsent the message appears in both conversation transcripts: yours and your recipient’s.
Unsending removes the message from your recipient’s device.
If the person you’re messaging is using a device with iOS 15.7, iPadOS 15.7, macOS 12.6, watchOS 9, or earlier, the original message remains in the conversation. When you unsend a message, you’re notified that the recipient may still see the original message in the message transcript.