On a macOS Mojave machine that was used by a French user I changed the default language with
sudo languagesetup and then I enabled the "Show Input menu in login window" option.
Then I added a new user and in the logon screen I choose the language matching the US keyboard layout, so I'm able to insert the password correctly.
However in the Sign In with Your Apple ID window I'm unable to enter my Apple ID and the password because the keyboard layout is back to French.
So it is possible to change the default keyboard layout? Or at least, it is possible to switch the keyboard layout during the user setup (the menu bar is unavailable at this stage)?