You will need to add Audiences and Interests into Citizen Space before you can add them to your consultation. This step needs to be done by a site admin and if this has not been done yet, see how to add Interests and Audiences.
Once Audiences and Interests have been added they will appear in a list when you are creating your consultation on the 'Edit Consultation' page. At least one Audience and one Interest option is required before you can publish your consultation. You can add more than one by holding down the CTRL key (PC) or the CMD key (Mac) whilst making your selection.
Once you've finished, ensure that all the completed fields are saved by clicking the 'Save' button.