Flutter.h file not found

Hello all: I am working on a Flutter App with a team, and the App uses Firebase. When I try to run the App in Xcode, I get an error: Flutter/Flutter.h file not found from FLTFirebaseCorePlugin.h. The steps I followed to bring the project over to the Mac from the PC are:
Copied the entire directory for the project
Open the project on the Mac in Android Studio
Run flutter pub get
Open a terminal, cd to the iOS folder
run pod install

but no joy. Can anyone offer any advice? I did have to set the paths to the Dart and Flutter SDKs on the Mac explicitly, and flutter doctor says all is OK, so stuck.

Thanks for any and all input.

i have the same problem have you get solution please ?