The visibility of Lookup Relationship fields on ZenDesk HelpCenter

I am encountering a problem regarding the display of a Lookup Relationship field on the Submit a Request form in the ZenDesk Help Center. I created a Lookup Relationship field that enables support agents to tag customer organizations as a ticket field from the list of SalesForce synched organizations. However, when I attempted to display this field on the Submit a Request form in the Customer Center, I was unable to do so. The ability to grant end-users the permission to edit the field is disabled in the field settings.