Unknown error WooCommerce API Integration

I want to create a custom dashboard using API in WooCommerce. I am not much aware of PHP. I am doing it myself following the reference article WooCommerce API Integration cloudways.com/blog/custom-dashboard-using-woocommerce-php-rest-api/ I am getting an unknown error in the index.php file. $query = ['date_min' => '2018-11-01', 'date_max' => '2018-11-30'>; $sales = $woocommerce->get('reports/sales', $query); $sale = $sales[0]["total_sales">; }