Ah, and you
need to do the recent firmware update before a 'factory reset', because of the May 25th 2023 mandatory Kobo update (I think they added TLS 1.3 support or something, to talk with their webservers). Which would make it impossible to finish the enrolment wizard on the e-Reader with older firmware.
E.g. this Kobo FAQ:
I got a message from Kobo about updates to my device. What should I do?