Hey there,
To unsend or edit text messages, you must be using iMessage with iOS 16 or later. If your recipients have devices with earlier versions of iOS, they receive follow-up messages with the preface “Edited to” and your new message in quotation marks. SMS messages can’t be unsent or edited.
You can undo a recently sent message for up to two minutes after sending it.
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.
If the person you’re messaging is using a device with iOS 16 or later, unsending removes the message from their device.
If the person you’re messaging is using a device with iOS 15.6 or earlier, iPadOS 15.6 or earlier, macOS 12 or earlier, or is using SMS, 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.