I keep getting the screen bellow when trying to use Facebook login. I'm trying to use AppAuth for Android ( https://github.com/openid/AppAuth-Android ) it mentions a domain URL but it is an Android app. Trying to use the OAuth2 specifications. Used Auth endpoint "https://www.facebook.com/dialog/oauth" and token endpoint "https://graph.facebook.com/v2.10/oauth/access_token". Any ideas, of what it could really be. Thanks for the help.
Lead maintainer for AppAuth-Android here. Facebook auth isn't directly supported by AppAuth, as they don't support the recommendations of RFC 8252. It is possible to make it work, see my demo.
My general recommendation would be to use the Facebook SDK if your app does not have an associated website. If the app has an associated site, perform the authentication via your site (in a custom tab) and then pass the necessary auth tokens back to the app.