Change the itemprop schema microdata attribute for navigation menu items

functions.php

<?php

/* @link https://anythinggraphic.net/change-navigation-menu-item-url-itemtype-schema-microdata/
/* Change microdata for specific menu items
----------------------------------------------------------------------------------------*/
add_filter( 'nav_menu_link_attributes', 'ag_menu_item_attributes', 10, 3 );
function ag_menu_item_attributes( $atts, $item, $args ) {
	// The ID of the target menu item
	// Remove this to target all menu items
	$menu_target = 123;
	
	// Remove if statement to target all menu items
	if ($item->ID == $menu_target) {
		// Since this is a mailto: link, we need it to be blank
		$atts['itemprop'] = 'URL or EMAIL or SOMETHING'; //schema.org
	}
	return $atts;
}