After you build the gallery, you become the possibility to export it to different file formats and to a specific folder on your hard drive. The method you need to choose is exporting the gallery to a folder because you have the HTML file which contains the gallery code. Simply open that HTML file, copy the code, then open the main page of your website and paste the code between the <body> / </body>
tags. Make sure that when you do this, all the other website's elements remain in their position and work correctly.