Flex 4.19.2 version

my build is not showing the flex icon after I double clicking on an imported object.
but when I open the flex sample project, the flex icon/button is showing up.so, the point is. I cannot add flex on objects because no flex button to click. Im using flex 4.19.2 version

In content , Static Mesh right mouse butt choice Create Flex Static Mesh.

257282-tim截图20181022140701.png

Thanks you