App Domains in Facebook Apps setting Home › Forums › Social Networks › Facebook › App Domains in Facebook Apps setting Tagged: App Domains, Facebook setting This topic contains 0 replies, has 1 voice, and was last updated by Eric Smith 1 year, 9 months ago. Author Posts December 12, 2017 at 1:04 pm #1046 Eric SmithKeymaster I want to add the ability to ‘login with Facebook’ to my site. But I am confused when I register my site in Facebook Apps. What should I input into App Domains? the app domain is your domain name. Before you enter your domain, first click on Add Platform, select website, enter your site URL and mobile site url. Save the settings. Thereafter, you can enter the domain name in the App domains field. Author Posts You must be logged in to reply to this topic.