Step1: Choose the template and get into builder.
Step2: 2nd last tool of the toolbar at the left corner of your page presents an option to Facebook Comment. Before choosing that, click on the block where you want to insert your Facebook Comment.
Step3: Click on 'Facebook Comment'. With this, Facebook Comment section will be added to your page.
Step4: You are free to drag this Facebook comment anywhere to your page.
Step5: Facebook Comment settings
1. Give single click on the inserted section and you will be provided with the toolbar to manage settings for your Facebook Comment section.
2. Here you can add your app ID and thus comment will be added to your page.