If you want to test your project on a local server before moving it to FB, you have this option. The company provides a test player that can be configured with a bit of effort and attentiveness, after which the game will be playable in a browser. Nevertheless, it is recommended to test your project running on Facebook infrastructure, and you will not need approval before you do this. Just upload the .zip file with the testing build, push it to production, and try it out. At this point, you are free to see how your game runs, and can even share the link with other users to get their opinion of it.