This Seeking Tech guide will explain how you can use the cross-save feature of Metaphor ReFantazio on the PlayStation 4 and PlayStation 5.
For the first step, make sure you are using the same PSN account for the PS4 and PS5 versions of Metaphor.
Once you are ready, open the version with the save file that you want to transfer over. From the main menu, select Load Game and then select the save file.
You then need to manually save to the Network Data slot.
Afterwards, open the other version of Metaphor. When you go to the Load Game option, you should see the cross-save file on the Network Data slot.