in flutter-desktop-embedding , I am a windows environment, I can run it, but I don't know how to build an exe file. I want to know what to do.
If you flutter build or flutter run a desktop project, you're already building a .exe; that's what's being launched by flutter run. You can find it in the build directory of the project (e.g., build\windows\x64\Debug\Runner\Flutter Desktop Example.exe for the FDE example app).