For 3ds Max 2019, plugins are installed in C:\ProgramData\Autodesk\ApplicationPlugins
So MAXtoA is in C:\ProgramData\Autodesk\ApplicationPlugins\MAXtoA
You need an Arnold license if you want to kick without watermarks.
3ds Max doesn't include an Arnold license that you can use with kick. 3ds Max just automagically renders without a watermark, as long as you render in the 3ds Max user interface.
// Stephen Blair
// Arnold Renderer Support