Finally got it done.
NB: this might sound stupid but make sure that the USB ethernet adapter is plugged into the car, ethernet cable into your laptop. DUH! don't know why I tried to do it the other way round.
I could not make Firefox work, but used winscp, once I downloaded the files I could generate the codes, no problem.
Unfortunately the codes did not work as I discovered my CIC was script activated.
In the end I had to us FStool, but not before a few issues. FStool did not see the donor vin, which was strange, but with a little help from Pl@y3r from another forum. I had to use FStool to first set vin and then check FSC and that forced the CIC to use donor vin and accept codes.
A mission but well worth it.