Here we will not fetch user credentials from cred.json or from token.pickle file, Considering will get the authorization token from front-end will embed this within our lambda_function and will create a credentials object. THis implementation helps to create REST APIs and Lambda Functions as well.
Lambda Functions accepts zip file so we will create a zip file out of this folder and will upload, test
pip install -t . --upgrade google-api-python-client google-auth-httplib2 google-auth-oauthlib