The Easy Extension program requires a U.S. address in order to process your extension electronically.
If you have a U.S. address that you can use, then you can just use that address (you can file your actual return with a different address, i.e. your foreign address). Otherwise, you can paper file an extension form using the form below. It is a very simple form to fill out and you can write in your foreign address.
You can also electronically file an extension using the IRS Free Fillable Forms - you will have to create an IRS account and go through the filing process with them, but you can indicate a foreign country on this form and electronically file. Note: You will need to choose the option for income over $66,000 even if that doesn’t apply.
You also may qualify for an automatic two-month extension by reason of being out of the country, but you would need to use TurboTax desktop software (not online) to attach the requirement statement when you file your actual return.