Are you asking how to answer the screen where it asks "Tell us the
state you lived in on December 31, 2015" (state of residence)?
If
so, in the dropdown menu there scroll all the way down to the bottom of
the menu past Wyoming, and you will see "Foreign or US Possession."
(See screen image #1 below.)
When you get to the mailing address
screen, you chose "foreign country" in the dropdown menu for "type of
address", and the boxes will reformat so you can select your country,
international postal code, etc. (See screen image #2.)
The
phone field on that mailing address screen will only take a
USA-formatted phone number, so if you have an international number you
may not be able to enter it and can leave it blank. A phone number is
not required to file, and the IRS doesn't phone for initial contact
anyway.
