Set a custom return URL for canceled orders on WooCommerce

wc-customer-cancel-payment-url.php

/* Paypal cancel order redirect */
add_filter( 'woocommerce_get_cancel_order_url_raw', 'paypal_canceled_redirect' );
function paypal_canceled_redirect(){ 
	// Replace the URL below with the one you'd like to return to after a canceled order.
 	return "https://woocommerce.com";
}