want asking, i am from malaysia and stay in TH, already got visa 90 days non-imm b and work permit, do we need to apply 1 year visa multiple entry or its automatic?

Hello Thailand Visa Advice - And Everything Else community. Thanks for all the help so far.

I wanted to know if anyone here has gone through the process for a "90-day Non-immigrant B visa (conducting business)".

This is the visa usually used for taking a meeting in Thailand, but not for working in Thailand.

I have a legitimate company able to offer me a Letter of Invitation and any other documents required.

A couple of questions:

1) Can this be applied for at an embassy abroad? All or some? Currently I am looking at Hanoi.

2) What additional documents are required besides the invitation letter?

Thanks!

Dave