USD withdrawals are available in two forms:
You can withdraw to a USD card
You can withdraw to a US Bank account, if you have a Social Security Number (SSN)
A registered SSN, or Social Security Number, is a unique identification number issued by the U.S. government in order to identify US residents.
If you don't have an SSN, the only option for withdrawal is to withdraw directly to your debit card - the app gives you this option when you select the payment method.