To use a shortcode inside your theme file or a PHP template, you need to know which page template file you want to insert the shortcode into. This could be a custom template file that you’ve created or one of the default page templates that comes with your WordPress theme. Once you have located the page template file, open it in a text editor such as Notepad. To insert the do shortcode, simply copy and paste the PHP function.
<?php echo do_shortcode('[sp_easyaccordion id="x"]'); ?>