Retrieve data from bricked Z Ultra c6802

Hello everyone,
recently a friend gave me her bricked phone. I thinks it is soft bricked(not 100% sure).
So, here is the fact, when it turns on it gets in a bootloop, always in the purple screen after SONY and XPERIA screens.
The problem is, there is no recovery, there is no root, bootloader is locked, usb-debug is probably inactive. So, i cant retrieve data with adb or windows.
But i can access fastboot.
What can i do to retrieve the data?
Give me your ideas guys.