Add this code into header.php of your child theme.

Please make all changes to the child theme files, and do not add the code directly to the theme files, otherwise after updating the theme your fixes will be lost

header.php

// Groovy Menu integration code
if ( function_exists( 'groovy_menu' ) ) {
	groovy_menu();
}
Note: You can find the child theme for the Shopkeeper Theme in the Groovy Menu > Integration section