https://cloud.google.com/docs/authentication/provide-credentials-adc#how-to

Application Default Credentials (ADC) is a strategy used by the Google authentication libraries to 
automatically find credentials based on the application environment. The authentication libraries 
make those credentials available to Cloud Client Libraries and Google API Client Libraries. When you 
use ADC, your code can run in either a development or production environment without changing how 
your application authenticates to Google Cloud services and APIs.

# logging into your desired email and setting up the project
gcloud auth login
gcloud config set project PROJECT_ID

# get current project
gcloud projects list
gcloud config get-value project

# Create local authentication credentials for your Google Account:
gcloud auth application-default login
Response ==> Credentials saved to file: [<PATH>/.config/gcloud/application_default_credentials.json]

# Install API keys client library
pip install google-cloud-api-keys

# Enable the "API Keys" API on google cloud
# Enable the "Cloud Storage" on google cloud

# Run "create_api_key.py" python file
Successfully created an API key: projects/PROJECT_ID/locations/global/keys/API_KEY