As per phone , Please see below message from our shipper as per below.
GST 6% is only applicable for local shipment and if you unable to provide K2 for the shipment.
As this is Thailand shipment your forwarder will provide the K2 however please check with them. If the forwarder able to provide then the 6% GST is not applicable
So , can you please make sure with your team for K2 process will not have any problem.