Since you received over $100,000 from a foreign person you are required to file a Form 3520. It form has the same due date as your tax return. The form can only be printed and mailed to the IRS, the address on where to mail is in the Form 3520 instructions.
Go to this IRS website for the Form 3530 - https://www.irs.gov/forms-pubs/about-form-3520
