Authentication for Google Directory using API key - oauth

Question

I'm attempting to write a script that will add G Suite accounts, but I want to do it without redirecting to Google to authorize each time the form is submitted. Is there a way to authorize within a script? I attempted authorizing using an API key but was getting a 401 Error - Login Required
Using oAuth and being redirected to Google works:
from __future__ import print_function
from googleapiclient.discovery import build
from httplib2 import Http
from oauth2client import file, client, tools
# If modifying these scopes, delete the file token.json.
SCOPES = 'https://www.googleapis.com/auth/admin.directory.user'
def main():
store = file.Storage('token.json')
creds = store.get()
if not creds or creds.invalid:
flow = client.flow_from_clientsecrets('creds.json', SCOPES)
creds = tools.run_flow(flow, store)
service = build('admin', 'directory_v1', http=creds.authorize(Http()))
print('Adding user...')
#create a user
service.users().insert(body={
"name": {
"givenName": "John",
"fullName": "John Smith",
"familyName": "Smith",
},
"password": "password",
"primaryEmail": "testuser#domain.com",
"changePasswordAtNextLogin": True,
}).execute()
if __name__ == '__main__':
main()
Using my API key which returns a 401 Error
API_KEY = 'key'
def main():
service = build('admin', 'directory_v1', developerKey=API_KEY)
print('Adding user...')
#create a user
service.users().insert(body={
"name": {
"givenName": "John",
"fullName": "John Smith",
"familyName": "Smith",
},
"password": "password",
"primaryEmail": "testuser#domain.com",
"changePasswordAtNextLogin": True,
}).execute()
if __name__ == '__main__':
main()

Answer 1

The first thing you need to understand is the difference between private and public data. Private data is data that is owned by a user and requires that you have the users permission to access. Public data is not owned by anyone. You can use an api key to access public data but not private data.
if you check Users: insert you will notice it states.
Authorization
This request requires authorization with the following scope (read more about authentication and authorization).
Scope
https://www.googleapis.com/auth/admin.directory.user
So this is a method that requires authentication. You have two options Oauth2 and request access of the user or to use a service account. A service account is like a dummy user this dummy user is granted access via domain wide delication it is normally used for server to server communication where there is no user to authenticate the code. I suggest you look into setting this up.