How to Redirect specific category product pages to cart page in Woocommerce
Better to use template_redirect hook. To target specific product category(ies), you can use WordPress has_term() conditional function. For cart url, is better to use WooCommerce function wc_get_cart_url()...
So in the code below define your product category(ies) term(s) name(s), slug(s) or Id(s):
add_action( 'template_redirect', 'ts_redirect_product_pages' );function ts_redirect_product_pages() { $categories = array('my-category-1', 'my-category-2'); if ( is_product() && has_term( $categories, 'product_cat' ) ) { wp_safe_redirect( wc_get_cart_url() ); exit; }}Code goes in functions.php file of the active child theme (or active theme). It should work.