ERROR 9 : License not found

Hello,
I've seen a lot of post about this error but none was talking about linux version.
I got this error while trying to launch CADFEKO (even launching POSTFEKO, EDITFEKO etc...)

the thing is I'm on a Linux machine (Ubuntu MATE 20.04) and i checked my license several times and the adress match with the ethernet adress of my computer.

I've tried to follow every tutorials but most of them are about a Windows version, the only way i've not tried is to change the OS on my computer but i can't do it.
Can you help me please ?