The GSS is the receipt from your payment for the visa made to Bank Ayudhaya. You get this on-line as follows:
log in to your profile atustraveldocs.com/th
click "new application/schedule appointment", continue choose "immigrant visa", continue click "K Visa Address Registration " select Visa Class complete the passport details specify documentation delivery type your virtual account number in the receipt number box.
print out the address registration confirmation page or the GSS Address registration.