I am getting below error in debug mode. Please can any one help me with this, I am working on this from lart two day, but no luck.

Notice: price was called incorrectly. Product properties should not be accessed directly. Backtrace: require('wp-blog-header.php'), require_once('wp-load.php'), require_once('wp-config.php'), require_once('wp-settings.php'), do_action('wp_loaded'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_Form_Handler::add_to_cart_action, WC_Form_Handler::add_to_cart_handler_variable, WC_Cart->add_to_cart, do_action('woocommerce_add_to_cart'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, WC_Cart->calculate_totals, do_action('woocommerce_before_calculate_totals'), WP_Hook->do_action, WP_Hook->apply_filters, call_user_func_array, GWP_Custom_Product_Tabs->add_custom_price, WC_Abstract_Legacy_Product->__get, wc_doing_it_wrong Please see Debugging in WordPress for more information. (This message was added in version 3.0.) in /home/example-com/public/wp-includes/functions.php on line 4196