Fastboot flashing of Jolla C2

Hello. I just got a C2 and the device does not register touch from the first boot. I managed to go through with a USB mouse connected but wifi doesn’t work.
As I saw on that thread, some user pointed to follow this guide to flash the device.
The problem is that I can’t enable developer mode like many users so I am stuck on step 2.
I can’t even install any app since I can remove mouse-connect to Mac but then there is no file manager to do anything (not that it would help anyway).
Is there any solution here?