Dear Sandra Villegas,
Thanks for your concern,
El Salvador passport holder can apply for visa online at get visa stamp and visa sticker on arrival with us as normal
Apply visa online, You will get visa stamp on the passport upon arrival, All you need to do is fill your
information in the form and make payment online.
After that, we will send You the approval letter via email, please print it out to board the plane and use
it to get visa stamp on the passport upon arrival.
Please try at my link: https://www.vietnam-evisa.org/apply-visa.html
Stepfano Tran (Mr. )