Flux checkout - Move the express checkout button so that it is displayed on all the steps.

functions.php

<?php
/**
 * Flux checkout - Move the express checkout button so that it is displayed on all the steps.
 *
 * @return void
 */
function iconic_flux_move_express_checkout_button() {
	remove_action( 'woocommerce_checkout_before_customer_details', array( 'Iconic_Flux_Core', 'express_checkout_button_wrap' ) );
	add_action( 'flux_after_header', array( 'Iconic_Flux_Core', 'express_checkout_button_wrap' ) );
}
add_action( 'init', 'iconic_flux_move_express_checkout_button' );