CODE EXAMPLE FOR PHP

woocommerce buy product skip cart

add_filter('add_to_cart_redirect', 'lw_add_to_cart_redirect');
function lw_add_to_cart_redirect() {
 global $woocommerce;
 $lw_redirect_checkout = $woocommerce->cart->get_checkout_url();
 return $lw_redirect_checkout;
}