Deductions & credits

Are you saying you were located overseas while working for this employer?  What mailing address is reported on your W-2?   In the TurboTax program W-2 section, it only asks you for the employer's address, which does allow you to choose a foreign country.  See the 1st image below.

However, if you are referring to your mailing address as an employee, to edit the address, you would need to return to the My Info section in the program.  See 2nd image below.