I sent a text message it was delivered to the recipient and received. I clicked undo send before they opened it, is it retrievable?

Here is what Apple says.......Unsend a message

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, iPadOS 16 or later, or macOS Ventura, 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.

See “Undo a sent message…” here.

Use Messages on your iPhone or iPad - Apple Support

If the message is not in Show Recently Deleted, then it is gone.