Integration with Flexible Checkout Fields

Hi,

I am a developer working on Flexible Checkout Fields plugin.

We have received several reports of an error occurring when a customer uses your plugin and ours:
PHP Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'WC_GZD_Checkout' does not have a method 'set_formatted_billing_address' in ...\wp-includes\class-wp-hook.php on line 287

I checked the code and found the problem in the file:
/includes/compatibility/class-wc-gzd-compatibility-flexible-checkout-fields.php

It’s about this piece of code:

add_filter( 'woocommerce_order_formatted_billing_address', array(
  WC_GZD_Checkout::instance(),
  'set_formatted_billing_address'
), $priority, 2 );

There is no set_formatted_billing_address method in the WC_GZD_Checkout class that is passed to the filter. The same applies to the set_formatted_shipping_address method.

Customers think the problem is with the Flexible Checkout Fields plugin, as this part of the code only runs when Flexible Checkout Fields is activated.

Would you be able to improve it? We are open to cooperation with you regarding the integration of our plugins.

Greetings,
Mateusz