See also https://answers.atlassian.com/questions/221902/does-the-contact-administrators-form-form-work-in-jira-ondemand.

I'm trying to add a contact-administrators option to an OnDemand instance, but setting this option to ON in System > General Configuration > Options doesn't seem to do anything. I guess I'm expecting the "to request an account..." message on the login screen to link to a contact-administrators form, as I do see on my download/installed instances, but that does not work for me in OnDemand.

There is documentation at https://confluence.atlassian.com/display/AOD/Restricted+Functions+in+Atlassian+OnDemand that hints at this as unavailable, but it doesn't seem to address the "Contact Administrators" functionality directly.

The message that's displayed on the login screen for OnDemand, "To request an account, please contact your JIRA administrators", is not really valuable to a user who doesn't already know who those administrators are. And, the experience for an administrator trying to enable this is somewhat garden-path, in that everything on the System > General Configuration > Options would seem to imply that it should work as expected. If nothing else, it would be helpful to see that general configuration option removed or disabled.