WooCommerce - Auto add item to cart if threshold reached

<?php
  // Auto add-to-cart when total reaches a given amount
  // code goes in functions.php for your child theme
  add_action( 'woocommerce_cart_loaded_from_session', 'auto_add_free_product_to_cart', 40 );
  function auto_add_free_product_to_cart() {
    // site owner's data
    $min_cart_total = 100.00; // minimum cart value to qualify for the product
    $free_product_id = 1801; // your free product ID here
    if ( ! is_admin() ) { // do nothing if on dashboard
      $woocommerce = WC(); // avoid globals
      // find out if the product is already in the cart
      $found = false;
      foreach ( $woocommerce->cart->get_cart() as $cart_item_key => $value ) {
        $_product = $value['data'];
        if ( $_product->id == $free_product_id ){
          $found = true;
        }
      }
      $cart_total = $woocommerce->cart->cart_contents_total;
      if ($cart_total >= $min_cart_total) {
        // cart total is enough
        if ( !$found ) {
          // free product not found, so add it
          $woocommerce->cart->add_to_cart( $free_product_id );
        }
      } else {
       // cart total is not enough, maybe an item was deleted
        if ( $found ) {
          // user is not entitled to the free product
          $woocommerce->cart->remove_cart_item( $cart_item_key );
        }
      }
    }
  }