function example_create_object( $order_id, $contact_id ) {

    $data = array(
        'MyCustomField' => $order_id,
    );

    $object_id = wp_fusion()->crm->add_object( $data, 'ObjectType' );

    if ( ! is_wp_error( $object_id ) ) {
        update_post_meta( $order_id, 'salesforce_object_id', $object_id );
    }

}

add_action( 'wpf_woocommerce_payment_complete', 'example_create_object', 10, 2 );