The login-customer-id header is only supported in the new Google Ads API. This GitHub repo is for the AdWords API Ruby library, which doesn't support that header. You can find the Ruby library for the Google Ads API here: https://github.com/googleads/google-ads-ruby
The login-customer-id header is only supported in the new Google Ads API. This GitHub repo is for the AdWords API Ruby library, which doesn't support that header. You can find the Ruby library for the Google Ads API here: https://github.com/googleads/google-ads-ruby