hello,
First sorry for this return but this plugin wasn't develop by the HikaShop Team, but by
Sky Spider
, that can contact,
here
.
Now, here from your elements we can already find some elements about your current issue,
here
.
Make a "Ctrl + F" and look for "Unprocessable Entity", this will bring you some clues about your current issue.
Now, does your solution is in the plugin or your merchant account, or the payment server side, unfortunately we can't tell...
We hope that this will help you to solve your issue.
Regards