Most plugins have no functional overlap with the theme or site into which they are inserted. Menu plugins are different in that they are designed to actively substitute a theme’s existing menu functionality.
This functional overlap generally and unavoidably requires a snippet of code to be overwritten in the theme’s 'header.php' file. This ensures that the theme uses the plugin menu rather than its own. The process is quick and simple, and we provide a few guides for some popular themes over on our documentation page at the below link.
NOTE: Updating a theme will always rewrite the 'header.php' file back to its original form and reinstate the theme’s default menu. So, each time you update a theme, simply take a minute to paste the same Hero Menu shortcode snippet into the latest 'header.php' file and you will be good to go. Alternatively the integration can be done through a child theme instead which would prevent this change from being overwritten when the theme is update. You can find out some more info about WordPress child themes at the below link.
We'd always be happy to help with any integration questions or assist with the process itself if needed so please feel free to get in touch.