The Facebook build target makes it easy to publish Unity games to Facebook and to use Facebook functionality in your games. Using the Facebook build target, you can build your content either as a WebGL player, which you can then publish to facebook.com, or as a custom native Windows Standalone player, which you can the publish to the Facebook Gameroom client.
When the Facebook build target is selected, you automatically have access to the Facebook SDK in your scripts, which lets you interact with Facebook and access it’s social features.
To publish your game to Facebook, you first need to create a new App on the Facebook developer page. Once completed, this will give you an AppID, which you should paste into your Facebook PlayerSettings. Now, you can get an Upload access token from Facebook, on your app configuration page, under the Web Hosting tab. Also paste this into your Facebook Player Settings. This will allow you to upload your game to Facebook directly from the Unity Editor.
Access the Facebook Build Settings via the in the Build Settings dialog box (menu: File > Build Settings…). In the dialog box, select Facebook from the Platform list.
Here you can choose to build your content as WebGL or as a Windows Standalone for Gameroom. If you plan to upload your game, choose Package build for uploading, which generates a compressed package, which can be uploaded to facebook.
After making a build, the Upload last build to Facebook button becomes available. If you have correctly configured your AppID and Upload access token, you can click this button to upload your build to facebook. The Enter Comment for upload field lets you specify an optional comment to identify your build.
Once you have uploaded a build to Facebook, it will appear on your your app configuration page on Facebook, under the Web Hosting tab. Here you can choose to push your build to production or to stage partial rollouts to smaller percentages of your users.
When the Facebook build target is active, you can use the Facebook SDK in your scripts. This lets you share content on Facebook, track analytics events, use Facebook Payments and more. See Facebook’s documentation for more information on how to use the SDK.
Which version of the SDK to use can be selected in the Facebook PlayerSettings, which will show all versions which Facebook has made available for your version of Unity.
If you want to use a different build of the Facebook SDK then the one included by Unity by default, you can do that, as long as it at least version 7.9.1 (so it supports the Facebook build target). Just download a build of the SDK from Facebook, and drop it into your Assets Folder. Unity will detect this, and disable the built-in SDK. This will allow you to use the Facebook SDK outside of the Facebook build target, which you want to use Facebook features on other platforms facebook supports.