Use the "Add Pages" button top menu and open the "section" menu - select the most suitable page and it should auto insert as a "section" i.e. offset left from a normal page and at the bottom of the last section or chapter depending on what you have already. Simply click and hold the page, then drag it above the first chapter until you see a blue line appear and drop it. Its now a standalone page and opens before chapter one. If your forward text is more than one page... the text flow will open pages as needed.