I have a simple question. when I using metronic layout builder in react demo I couldn't find export option. all I see is preview and reset option. how should I use react demo ?? just customizing the demo ???
Yes, there are no export options in react version, you can get generated layout config in the code preview section which is placed lower.
Just copy generated config and place it into a file /src/_metronic/layout/LayoutConfig.js so you will get the required layout.