Check the Recently Deleted folder in the Messages app
Open Messages
Tap Edit or Filters
Tap Show Recently Deleted
Select the messages
Tap Recover
Restore from an iCloud backup
Go to Settings
Tap your name
Tap iCloud
Tap iCloud Backup
Check for an available backup made before the messages were deleted
Erase the iPhone
Set up the iPhone again
Choose Restore from iCloud Backup
Restore from a computer backup
Connect the iPhone to a Mac or PC
Open Finder on Mac or iTunes on Windows or older macOS
Select the iPhone
Choose Restore Backup
Pick a backup made before the messages were deleted
Check other Apple devices signed in with the same Apple ID
Open Messages on iPad, Mac, or another iPhone
Look for the missing messages
Contact your carrier
Ask whether message records or backups are available
Use a third-party recovery tool
Scan the iPhone or backup with a trusted recovery app