Alternatively, you might find the macos_ui
package a good fit for your needs.
This package provides widgets and themes that
implement the macOS design language,
including a MacosWindow frame and scaffold,
toolbars, pulldown and
pop-up buttons, and modal dialogs.

Building macOS apps

To distribute your macOS application, you can either
distribute it through the macOS App Store,
or you can distribute the .app itself,
perhaps from your own website.
As of macOS 10.14.5, you need to notarize
your macOS application before distributing
it outside of the macOS App Store.

The first step in both of the above processes
involves working with your application inside of Xcode.
To be able to compile your application from inside of
Xcode you first need to build the application for release
using the flutter build command, then open the
Flutter macOS Runner application.