You will need to upgrade to access the settings to enable video, changing settings is only available for people who:
• Have paid to remove the ads
• Have a valid iSitter Connect Premium subscription
In the "Remove Ads" button it will offer for you to remove the ads, and if you have signed in to iSitter Connect it will offer you a premium subscription.
Note that if you elect to subscribe to ISC Premium, you will no longer be able to change the settings once your subscription runs out (although this might well not be an issue if you have them how you want them),