Pass custom field to GeomyWP field when post is saved

Hi there,
I have created a custom field. A post is created by a user on the frontend and as part of that a custom field is created that contains a post code. I need to pass that field to a plugin called GeomyWP at the point the custom post is created. There are instructions here on how to do this:

http://docs.geomywp.com/gmw_pt_update_location/

However I have not been able to get them to work.

Currently my code is:

function gmw_update_post_type_post_location( $post_id ) {

// Return if it's a post revision
if ( false !== wp_is_post_revision( $post_id ) )
return;

// check autosave //
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
return;
}

//check if user can edit post
if ( !current_user_can( 'edit_post', $post_id ) )
return;

//get the address from the custom field "address"
$address = get_post_meta( $post_id, 'wpcf-expert-post-code', true );

//varify that address exists. Otherwise abort the function.
if ( empty( $address ) )
return;

//include the update location file file
include_once( GMW_PT_PATH .'/includes/gmw-pt-update-location.php' );

//make sure the file included and the function exists
if ( !function_exists( 'gmw_pt_update_location' ) )
return;

//Create the array that will pass to the function
$args = array(
'post_id' => $post_id, //Post Id of the post
'address' => $address

);

//run the udpate location function
gmw_pt_update_location( $args );
}
//execute the function whenever post type is being updated
add_action( 'save_post_experts', 'gmw_update_post_type_post_location' );

wpcf-expert-post code is the custom field created by the user and the custom post type is 'expert'

Do you think you could help with this?

Regards,

David Robinson