Now I see on the screen of the phone:
DEVICE STATE - locked
This is strange as I unlocked the phone yesterday.
I think at switching the phone on and off yesterday after unlocking, made the phone forget that it was unlocked.
So now I will unlock the phone in developer options again.
Thank you all for your help.
On Fedora you have to do everything as root
and in the final steps of installing /e/ one need to start the command with ./
For example: ./fastboot -w
./fastboot flash system system.img
and so on.