No, you cannot obtain a Vietnam visa on arrival unless you have a prior approval letter. Most foreign visitors to Vietnam must obtain a visa before entering the country. Before traveling, you must submit an application and obtain an approval letter from the Vietnamese authorities.
After receiving the approval letter, you can use it to obtain a visa on arrival in Vietnam at one of the designated airports. You will be unable to obtain a visa on arrival and may be denied entry into the country if you do not have this approval letter.
It is important to note that the process of obtaining a Vietnam visa can take several days, so plan ahead of time and apply well in advance of your intended travel dates.
If you have a travel plan to Vietnam, Vietnam e-Visa (visa online) is a wonderful choice thanks to its convenience. It is critical to research the specific Vietnam visa requirements to ensure that you have all of the required documentation and meet all of the entry requirements.