The generated code from FlutterFlow should run as a web application. However, we don't officially support Web for Flutter just yet.
Here are some of the known issues:
Scrolling issues occur in iOS Web
iOS video player and YouTube player may not work
Additionally, we don’t have the functionality to deploy a web app directly from within FlutterFlow. Here’s Flutter’s documentation on how to deploy to the web: https://flutter.dev/docs/deployment/web#deploying-to-the-web