operator not supported – PHP 7.2

Hello, regarding
Woocommerce Advanced Shipping. Since the update PHP 7 to 7.2 with wordpress 5.3.2 we have an error, we returned to version 7.0 while waiting for a solution thank you all !!.

• Line 91
• Message Uncaught Error: [] operator not supported for strings in /home/*****/www/wp-content/plugins/woocommerce-advanced-shipping/includes/class-was-method.php:91 Stack trace: #0 /home/*****/www/wp-content/plugins/woocommerce-advanced-shipping/includes/class-was-method.php(31): WAS_Advanced_Shipping_Method->was_match_methods() #1 /home/*****/www/wp-content/plugins/woocommerce-advanced-shipping/woocommerce-advanced-shipping.php(181): WAS_Advanced_Shipping_Method->__construct() #2 /home/*****/www/wp-includes/class-wp-hook.php(288): WooCommerce_Advanced_Shipping->was_shipping_method(”) #3 /home/*****/www/wp-includes/class-wp-hook.php(312): WP_Hook->apply_filters(”, Array) #4 /home/*****/www/wp-includes/plugin.php(478): WP_Hook->do_action(Array) #5 /home/*****/www/wp-content/plugins/woocommerce/includes/class-wc-shipping.php(122): do_action(‘woocommerce_shi…’) #6 /home/*****/www/wp-content/plugins/woocommerce/includes/class-wc-shipping.php(114): WC_Shipping->init() #7 /home/tru
• File /home/*****/www/wp-content/plugins/woocommerce-advanced-shipping/includes/class-was-method.php