| Name | Type | Description | Notes |
|---|---|---|---|
| r#type | Type | Button type. phone is Facebook only. (enum: url, postback, phone) | |
| title | String | Button label (max 20 chars) | |
| url | Option<String> | URL for url-type buttons | [optional] |
| payload | Option<String> | Payload for postback-type buttons | [optional] |
| phone | Option<String> | Phone number for phone-type buttons (Facebook only) | [optional] |