Thank you so much for using our theme. Elementor is third-party plugin and if you want to use it on your theme, you can make the custom template as well. We recommend you to follow this blog post to know how to use Elementor plugin with your theme. http://www.wpbeginner.com/plugins/how-to-create-custom-wordpress-layouts-with-elementor/ Hope this helps. If you need to add that code on the templates file, you can make own custom templates for it. https://developer.wordpress.org/themes/template-files-section/page-template-files/
Hope this helps.