@taxsavvy Amended tax returns can be filed at any time. However, if the amended return has a tax refund it must be filed within 3 years from the due date of the original tax return.
You should contact a TAC office in your area for assistance with the ITIN.
Go to this IRS website for TAC locations - https://www.irs.gov/help/tac-locations-where-in-person-document-verification-is-provided
