Welcome to the forum.
Who told you about the need to marry in Laos?
Perhaps consult with an immigration lawyer in Vientiane for information.
Or have a small official marriage ceremony in Laos at your wife's family home.Â
RDK Group in Vientiane can assist you in the application.
From what I can gather online, the spouse visa is available to spouses of Lao citizens who have registered their marriage overseas. In order to apply, the foreign marriage certificate must be authorized at the treaties and law department, Ministry of Foreign Affairs.
Type Laos spouse visa into your search engine and check out the information there.
There are plenty of companies who are capable of organizing your application.
The information I have given has been i place since 2018.