Once a creator submits a proposal, their audience demographics can be viewed by clicking the “View Account" link on the proposal. The demographics are only available from creators who are in your Manage tab.
Please note that the creator must also have their Instagram Insights connected in order for you to view their demographics.
Once you are on their account profile, you can drill down to the specific details of their audience demographics from the ‘Analyze’ tab at the top of the page.