@Sam *****
Proof of LOCATION is just what it says, so you are wrong.
You have to apply at the embassy/consulate that has jurisdiction at the LOCATION where you are.
Some countries have more than one embassy/location, others have one and some have none.
Countries that don't have an embassy/consulate in their country, always have an embassy/consulate in an other country that has jurisdiction in their country.
So sometimes you can even be in another country as where you apply, and sometimes being in the same country still can be wrong, like in Vietnam