Environment details

• OS type and version: OSX Sonoma 14.5
• Python version: python --versionPython 3.11.4
• pip version: pip --version 23.1.2
• google-auth-oauthlib version: pip show google-auth-oauthlib 1.1.0

Steps to reproduce

1. Create an instance of Flow from client config:
2. Generate an authorization url from Flow instance
3. Try to access code_verifier and it will be None

Code example

client_config = { "web": { "client_id": YOUR_CLIENT_ID, "client_secret": YOUR_CLIENT_SECRET, "auth_uri": "https://accounts.google.com/o/oauth2/auth", "token_uri": "https://oauth2.googleapis.com/token", "redirect_uris": [redirect_uri], } } flow = Flow.from_client_config( client_config, scopes=scopes, redirect_uri=redirect_uri) url, gen_state = flow.authorization_url(prompt="consent select_account", state=state) >>>flow.code_verifier is None >>>True

Stack trace

# example 

Making sure to follow these steps will guarantee the quickest resolution possible.

Thanks!