Code-Snippets-Functions/Execute a function on a child site/WooCommerce/deny-second-purchase-cart-checkout.txt

add_filter( 'woocommerce_is_purchasable', 'wc_deny_purchase_if_already_purchased', 9999, 2 );
  
function wc_deny_purchase_if_already_purchased( $is_purchasable, $product ) {
   if ( is_user_logged_in() && wc_customer_bought_product( '', get_current_user_id(), $product->get_id() ) ) {
      $is_purchasable = false;
   }
   return $is_purchasable;
}