https://www.uscis.gov/news/alerts/uscis-will-no-longer-accept-i-407-international-field-offices "Individuals who wish to voluntarily record abandonment of their lawful permanent resident (LPR) status must submit Form I-407 via mail to: USCIS Eastern Forms Center" "In very rare circumstances, a U.S. embassy, U.S. consulate, or USCIS international field office may accept a Form I-407 in person if an individual needs immediate proof that they have abandoned LPR status."