If the Panamanian passport holders want to apply visa at Vietnam Embassy, they should to know that:
Visa administrative Institution: Vietnam Embassy
Processing time: depends on you how fast you need. But for sure, you should make a call to Vietnam Embassy for details.
Required Documents: passport, money and 1 new envelope with stamp on it and your exact home address in order to avoid losing issues.
How to apply: please take a look at contact information of Vietnam Embassy below
EMBASSY OF VIETNAM IN EL DORADO, PANAMA
Address: Local 3, Piso 10, Edificio Banco Atlantico, Calle 50 y 53, Panama
Phone: (507) 265 2551
Fax: (507) 265 6052