Comment button?

Hello. I want to add a comment button. permalink. #respond

There is no such option in this plugin. So I wanted to change the “messenger” button. But I couldn’t do that. How do I change this code? to respond. Thanks

case 'messenger':
						$link                = urlencode( $permalink );
						$messenger_share_url = is_mobile() ? "fb-messenger://share/?link=$link?app_id=$this->fb_app_id" : "http://www.facebook.com/dialog/send?app_id=$this->fb_app_id&redirect_uri=$link&link=$link&display=popup";