How to add single wordpress cron event using php?

How to add single wordpress cron event using php?

add_action( 'woocommerce_thankyou', 'goaskle_auto_complete_orders' );

function goaskle_auto_complete_orders( $order_id ) {
 
wp_schedule_single_event( 
time() + 2 * DAY_IN_SECONDS, // after 2 days 
'goaskle_auto_complete_order', 
array( $order_id ) 
);
 
}
 
add_action( 'goaskle_auto_complete_order', 'goaskle_auto_complete_order' );
function goaskle_auto_complete_order( $order_id ) {
 
$order = wc_get_order( $order_id );
if( ! $order ) {
return;
}
 
if( 'processing' === $order->get_status() ) {
$order->update_status( 'completed' );
}
 
}

use in wordpress php coding