Tutorial to activate USB debugging: https://www.hardreset.info/devices/fairphone/fairphone-3/faq/faq/usb-debugging-fairphone/
Then you need to install adb on your computer (MacOS/Windows/Linux). And type those commands into your Terminal. There are plenty tutorials on youtube out there. NO you DON’T need to reset your phone and lose data. That’s the reason why I posted this way. For me a factory reset Is not an option.