Print an OAuth2 authorization URL for the marketing control plane.
mix google.oauth.authorize
mix google.oauth.authorize --redirect-uri http://127.0.0.1:8080/oauth2callbackEnv: GOOGLE_CLIENT_ID or GOOGLE_MARKETING_CLIENT_ID.
Optional: GOOGLE_OAUTH_REDIRECT_URI (default http://127.0.0.1:8080/oauth2callback).