```ruby
GDS::SSO.config do |config|
  config.user_model   = "User"
  config.oauth_id     = ENV["OAUTH_ID"]
  config.oauth_secret = ENV["OAUTH_SECRET"]
  config.oauth_root_url = Plek.find("signon")
end
```

Update the GDS::SSO template to use external_url_for
user
```ruby
GDS::SSO.config do |config|
  config.user_model   = "User"
  config.oauth_id     = ENV["OAUTH_ID"]
  config.oauth_secret = ENV["OAUTH_SECRET"]
  config.oauth_root_url = Plek.new.external_url_for("signon")
end
```
assistant