Thanks @Claude31 for your valuable input.

Hi Laurent! I didn't get any specific solution for the problem posted. But at last what I did which helped me in building my code was, I simply removed all the pods & package dependencies from my project. And then deleted the DerivedData Folder and cleaned the code, closed the Xcode. Then through terminal I run the command to clean the cache and then re-added all of them again. There were couple of errors related to framework which I figured out, and everything just worked perfectly.

Thanks Quinn with your help I got to know that the code is already Implementing PushKit and Notification Service Extensions. Yet am unable to take it to the solution. Can you highlight any other possibility or clarify the path to cross check (if possible) with the content I have shared above. Thanks in Advance!