How to initialization/Add Firebase in an existing project

Hello everyone,

After building IOS BUILD of the cocos project Successfully.

I added podfile using "pod init " in the project

then using “pod install” command to install pod in the project. which create the .xcworkspace file.

After opening the .xcworkspace file in the Xcode. I added firebase_cpp_SDKs framework in the project,Downloaded from this link " 将 Firebase 添加到您的 C++ 项目  |  Firebase Documentation " in step 4.

then, I am trying to add firebase in the AppDelegate.cpp and AppDelegate.h file but it shows error.

If anyone have any suggestion and any demo project in which firebase added.
Please share, Thanks