How to make payment of Tax Return

I am filing Form 1040-NR-EZ and Form 8843. At the same time, I am applying for ITIN.

I need to pay the tax I owe somehow, but it requires me to enter an SSN or an ITIN, which I don't have. For example, Direct Pay asks me to enter an SSN or an ITIN.

How can I make the payment?