You can delete text messages, attachments, and entire conversations from your iPad anytime, without affecting what your recipients see.
Tip: Use on your iPad.
In the Messages conversation list, do one of the following:
Swipe left on the conversation, then tap on your iPad.
Tap Edit in the top-left corner, then tap Show Recently Deleted.
Tap Automatically delete one-time verification codesApple Support article: Delete texts and attachments in Messages