Restore deleted messages
How do you restore deleted messages on a IPhone 12
iPad Pro 12.9-inch, 3rd Gen, Wi-Fi
Question marked as
If the messages are contained in a backup, restore the backup to recover the messages. If you sync messages with iCloud and you deleted them, they are gone.
When you restore a backup, you overwrite the current contents on your device.
Restore your iPhone, iPad, or iPod touch from a backup - Apple Support