I have followed the guide below to obtain a Google Ads API refresh token for my application.
Using the script below, everything worked, but the response only had an access token, while the refresh token was None.
from googleads import oauth2
import google.oauth2.credentials
import google_auth_oauthlib.flow
# Initialize the flow using the client ID and secret downloaded earlier.
# Note: You can use the GetAPIScope helper function to retrieve the
# appropriate scope for AdWords or Ad Manager.
flow = google_auth_oauthlib.flow.Flow.from_client_secrets_file(
'client_secret.json',
[oauth2.GetAPIScope('adwords')])
# Indicate where the API server will redirect the user after the user completes
# the authorization flow. The redirect URI is required.
flow.redirect_uri = 'https://www.example.com'
# Generate URL for request to Google's OAuth 2.0 server.
# Use kwargs to set optional request parameters.
authorization_url, state = flow.authorization_url(
# Enable offline access so that you can refresh an access token without
# re-prompting the user for permission. Recommended for web server apps.
access_type='offline',
# Enable incremental authorization. Recommended as a best practice.
include_granted_scopes='true',
# approval_prompt='force'
)
print("\n" + authorization_url)
print("\nVisit the above URL and grant access. You will be redirected. Get the 'code' from the query params of the redirect URL.")
auth_code = input('\nCode: ').strip()
flow.fetch_token(code=auth_code)
credentials = flow.credentials
print(credentials.__dict__)
The problem seemed to be that I have already completed these steps before.
The solution was to include approval_prompt='force' in flow.authorization_url(). After generating the authorization_url this way, the response included a refresh token as well.