I got following reply from Oracle:
Thank you for writing to Oracle Certification Program.
Please note voucher purchased from one country could not be redeemed in different country. You can submit the assignment from different country but cannot use the voucher.
We have changed the process of remitting assignments to make it more convenient for the candidate. Instead of waiting for upload permissions, please email your completed assignment to us directly at architect-submit_US@oracle.com
. Please be sure you have completed your essay exam (310-062) before sending us your completed assignment and include your Prometric test ID with your submission. To register for the essay go to prometric.com/sun.
In assignment email from Oracle, they asked me to email completed assignment to : firstname.lastname@example.org