.wgt file for flutter-tizen

Hi everyone. I’m kinda new here, so please bare with me here.
I recently started to develop an app for Samsung Smart TV using Tizen studio and flutter. Based on the documentation in order to deploy an app for Samsung TV, the app extension has to be a .wgt file extension. I tried to find the .wgt file in my project folder but couldn’t find it and it’s not created in the build process. So how can I create the .wgt file in tizen-flutter