Check iCloud backups if Messages in iCloud was not enabled
Restore an iPhone from an older backup that contains the deleted iMessages
Check other Apple devices signed into the same Apple ID
Use Spotlight search to look for message content or contact names
Ask the other person to resend the conversation or screenshots
Check notification previews on locked screens or in Notification Center
Review email or app notifications if message forwarding was enabled
Use third-party data recovery software if a backup is unavailable
Contact Apple Support for account and backup-related help