PHP 7.3 Support

I was curious of the PHP7.3 support? I upgraded my site to 7.3 last night and when items to cart I get a white screen with the following error.

2020/06/24 11:40:36 [error] 11716#11716: *825028 FastCGI sent in stderr: “PHP message: PHP Fatal error: Uncaught Error: [] operator not supported for strings in /var/www/sites/wp-content/plugins/wp-menu-cart-pro/includes/wpmenucart-woocommerce-pro.php:51
Stack trace:
#0 /var/www/sites/wp-content/plugins/wp-menu-cart-pro/wp-menu-cart-pro.php(533): WPMenuCart_WooCommerce_Pro->submenu_items()
#1 /var/www/sites/wp-content/plugins/wp-menu-cart-pro/wp-menu-cart-pro.php(388): WpMenuCartPro->wpmenucart_submenu_item()
#2 /var/www/sites/wp-includes/class-wp-hook.php(287): WpMenuCartPro->add_itemcart_to_menu(‘<li id=”menu-it…’, Object(stdClass))
#3 /var/www/sites/wp-includes/plugin.php(206): WP_Hook->apply_filters(‘<li id=”menu-it…’, Array)
#4 /var/www/sites/wp-includes/nav-menu-template.php(259): apply_filters(‘wp_nav_menu_top…’, ‘<li id=”menu-it…’, Object(stdClass))
#5 /var/www/sites/wp-content/themes/Divi/functions.php(6461): wp_nav_menu(Object(stdClass))
#6 /var/www/sites/wp-content/themes/Divi/functions.php(6294): et_divi_get_top_nav_items()
#7 /var/www/sites/wp-incl” while reading upstream, client: 71.74.68.96, server: domain.com, request: “GET / HTTP/1.1”, upstream: “fastcgi://unix:/run/php/php7.3-fpm.sock:”, host: “www.domain.com”