I am trying to fill the Form 8615, there is a box needs parent's ssn, however, my parents are foreigners and they don't have ssn. What should I fill in this box?

I saw there is a question asked before, but it could not solve my problem.

As I tries to continue to the E-file, 8615 form keeps warning me to fix my parent's ssn, but they dont have any. I downloaded the file and hand written them and uploaded onto the website, but the website does not have any option for me to manually replace those file.

Is there any method I can do in order to finish my tax?