CRITICAL Uncaught Error: Call to a member function menu_item

Hi do you know why we have this error message ?

2023-03-02T12:00:21+00:00 CRITICAL Uncaught Error: Call to a member function menu_item() on null in …/wp-content/plugins/woocommerce-menu-bar-cart/wp-menu-cart.php:707

Stack trace:

#0 …/wp-content/plugins/woocommerce-menu-bar-cart/wp-menu-cart.php(783): WpMenuCart->wpmenucart_menu_item()

#1 …/wp-includes/class-wp-hook.php(308): WpMenuCart->wpmenucart_ajax()

#2 …/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters()

#3 …/wp-includes/plugin.php(517): WP_Hook->do_action()

#4 …/wp-admin/admin-ajax.php(188): do_action()

#5 {main}

thrown dans …/wp-content/plugins/woocommerce-menu-bar-cart/wp-menu-cart.php à la ligne 707

Thanks for your support,
Mike