For preview only `OrderPreviewV1Req.to`. Target currency + ratio ratio. Forbidden is confused with the order `CreateParam`: the `to` of the order must be `amount`, and there is no `ratio` field.
| Name | Type | Description | Notes |
|---|---|---|---|
| Asset | string | Target currency symbol; often corresponds to `recommend_v2.*[].schemes[].name` in config. | |
| Ratio | string | The weight ratio of the target currency in the portfolio, decimal string (such as `0.2`, `0.5`). Often consistent with the `schemes[].ratio` of a strategy under `recommend_v2` of `GET /asset-swap/config`. |