I am currently in Vietnam as a tourist, should I apply using the home country (USA) embassy or Vietnam embassy. How would I show proof of the current location? Thanks in advance.
TLDR : Answer Summary
If you are currently in Vietnam as a tourist, you should apply for your visa at the embassy or consulate of Vietnam, not the USA. To prove your current location, present your passport entry stamp and any accommodation booking, such as a hotel or Airbnb reservation.