Add function to Dokan ajax class

This is the core developer of Dokan. There is a much simpler way to use your custom function for this case. This dokan_add_shipping_tracking_info action can be found within this template : /rafsuntaskin.com/wp-content/plugins/dokan/templates/orders/details.php .

You can copy this into your theme and change the action to your custom function like this :
rt_custom_add_shipping_tracking_info replaces dokan_add_shipping_tracking_info
Then add a custom wp ajax hook in your theme’s functions.php
wp_ajax_rt_custom_add_shipping_tracking_info and use the custom function as callback.

Thanks