Check the Recently Deleted folder in Messages
Open the Messages app
Tap Edit or Filters
Tap Show Recently Deleted
Select the messages to recover
Tap Recover
Restore from an iCloud backup
Go to Settings
Tap General
Tap Transfer or Reset iPhone
Tap Erase All Content and Settings
Set up the iPhone again
Choose Restore from iCloud Backup during setup
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
Open Messages on an iPad, Mac, or another iPhone using the same Apple ID
Look for the deleted messages if they were not yet synced out
Contact your carrier
Ask whether message records or SMS logs are available
Use a third-party recovery tool
Install a reputable iPhone data recovery app
Scan the device or backup
Recover messages if the tool finds them
Turn off Messages in iCloud before restoring a backup if needed
Go to Settings
Tap your name
Tap iCloud
Tap Messages
Turn off Sync this iPhone