Add body class

I am using the professional version of CP Google maps and I need to add a css class to the body tag whenever a map is added to a post or page.

I found this code but struggle to find a place to add it:

add_filter( 'body_class','my_body_classes' );
function my_body_classes( $classes ) {
    $classes[] = 'class-name';
    $classes[] = 'class-name-two';
    return $classes;
}

Can you point me to a function to add this code or another way to get a class added to the body element only if a map is displayed.

https://ww.wp.xz.cn/plugins/codepeople-post-map/