The (German) translation is missed in the screen of "Create a new user"
Username = Benutzername Password = Passwort Email = E-Mail
See the wording in the table before
This does indeed seem to be hardcoded:https://github.com/matomo-org/matomo/blob/8c792dcf02424fce9b5a88c571c8f5c76295b710/plugins/UsersManager/angularjs/user-edit-form/user-edit-form.component.html#L39-L86