Messages
How do I get my old messages from other phone I no longer have access to
iPhone SE, iOS 14
Question marked as
If both phones are using the same Apple ID, if you were syncing Messages to iCloud, have you gone to Settings/Your Name/iCloud, and turned Messages syncing on?
If you weren't syncing Messages to iCloud, do you have a backup of the old phone that you can restore from? Restoring from a backup erases all data currently on your device. Any data newer than when the backup was made will be erased. A restore is an all or nothing restore. You can't access a backup to see the contents and only restore certain files.
Backup - Restore your device from an iCloud or iTunes backup.