This tutorial will help you get URL of live Facebook videos :
Step 1 : Go to Facebook
Step 2 : If you have created an account with Facebook, login, else Signup
Step 3 : Now create a live video
Step 4 : Once your video is created, right click on it, and select Show Video URL.
Step 5 : Copy the URL shown in the box and paste it in the respective field of the app page