After you finished your project, you want to run it on the GetWrite app. In order to do that, you need to export your project. This article will show you how to do that.
Open the editor view of your project and hover over the "Compile" option in the navigation bar. A dropdown menu will appear, where you can select the "Compile project and export" option. This will open a dialog that allows you to export your project. Note that the compilation can take a while, depending on the size of your project and - regarding the download of the packaged .GWP file - your internet connection.