Enum describing the preview type. Next Id: 4

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/enums/preview_type.proto)

| Enums ||
|---|---|
| ## `UI_PREVIEW` | Request a URL to a preview in the Google Ads UI. The generated URLs are shareable. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |
| ## `YOUTUBE_LIVE_PREVIEW` | Request a URL to a preview of the ad in YouTube. The generated URLs are shareable. |