Vietnam Visa During a Layover 2026 — Transit Hub Entry Port Error: SIN, ICN, NRT, DOH, DXB

Transit hub entry port error guide — 11-row route table covering SIN (AU/NZ), ICN (CA/US), NRT (US/CA Pacific), DOH/DXB (UK/IE via Qatar/Emirates), CDG/FRA (CA/EU via Europe), step-by-step how to find correct port in booking confirmation, and what to do if wrong port already submitted or approved.