Before you can run the project, follow the for Facebook Android SDK to set up a Facebook app. You can skip the build.gradle changes since that's taken care of by the rnpm link step above, but make sure you follow the rest of the steps such as updating strings.xml and AndroidManifest.xml.
3.2 iOS
Follow steps 3 and 4 in the for Facebook SDK for iOS.
If you're not using cocoapods already you can also follow step 1.1 to set it up.
If you're using React Native's RCTLinkingManager
The AppDelegate.m file can only have one method for openUrl. If you're also using RCTLinkingManager to handle deep links, you should handle both results in your openUrl method.