WooCommerce redirect to cart if trying to add a 'sold individually' item that is already in the cart

file.php

//not sure what to do with this code snippet? See https://www.thathandsomebeardedguy.com/what-do-i-do-with-these-code-snippets/

add_filter( 'woocommerce_add_to_cart_sold_individually_found_in_cart', 'handsome_bearded_guy_maybe_redirect_to_cart' );

function handsome_bearded_guy_maybe_redirect_to_cart( $found_in_cart ) {
 if ( $found_in_cart ) {
  wp_safe_redirect( wc_get_page_permalink( 'cart' ) );
  exit;
 }
 return $found_in_cart;
}

problem with this is if users hit the back button and retries to add the same product it doesn't goes to checkout page. instead goes to cart.