Missing step in description of 2FA activation

The GitLab documentation for enabling 2FA sign-on validation assumes that the user always has access to a smartphone: it one is not available, U2F devices, such as a Ubikey, can't be configured.

The problem is that all the applications listed as capable of generating the PIN needed to be input before the U2F device can be selected can only be run on Android smartphones, which means that those of us who prefer ruggedised phones, such as the Samsung B2100, cannot generate the required PIN. Please extend this list to include applications that can be run, preferably from the command line, on Windows, iOS and Linux computers. Having a command line tool seems appropriate it is not something that is needed every day.