# HelloSign::SubOAuth OAuth related parameters. ## Properties | Name | Type | Description | Notes | | ---- | ---- | ----------- | ----- | | `callback_url` | ```String``` | The callback URL to be used for OAuth flows. (Required if `oauth[scopes]` is provided) | | | `scopes` | ```Array``` | A list of [OAuth scopes](/api/reference/tag/OAuth) to be granted to the app. (Required if `oauth[callback_url]` is provided). | |