UPDATE DOLPHIN IN BATOCERA!

How do I upgrade the Dolphin emulator in Batocera?

I believe you would need the bios package from batocera 5.20. From what was told, do not install external sources since it may break.

And how do I get the Bios package from Batocera 5.20?

The latest versions of Dolphin are using the QT5 library and we are working on this update.