Tip:
  To use the simulator, you will need to 
  embed the Debug version of the Flutter frameworks in your
  Debug build configuration. To do this 
  you can use $(PROJECT_DIR)/Flutter/$(CONFIGURATION)
  in the Framework Search Paths (FRAMEWORK_SEARCH_PATHS)
  build setting. This embeds the Release frameworks in the Release configuration, 
  and the Debug frameworks in the Debug Configuration.

You must also open MyApp.xcodeproj/project.pbxproj (from Finder) 
  and replace path = Flutter/Release/example.xcframework;
  with path = "Flutter/$(CONFIGURATION)/example.xcframework";
  for all added frameworks. (Note the added ".)

Embed the frameworks

The generated dynamic frameworks must be embedded
into your app to be loaded at runtime.