How to change country of my iTune Account VN to USA none??
I want change country of my iTune Account VN to USA billing "none". How to make it?
You are currently in the US ? If not then you cannot use the US store.
If you are then put your US payment details on your account, and after doing so you should be able to select 'none' : Why can’t I select None when I edit my Apple ID payment information? - Apple Support
When you change the country or region of an existing Apple ID, you must provide a payment method and update your billing options. If you want to remove your payment method after you change the country or region, you can change your payment information to None.