| Name | Type | Description | Notes |
|---|---|---|---|
| type | string | ||
| title | string | Button label (20 chars max) | |
| url | string | Target URL (required when type is url) | [optional] |
| payload | string | Postback payload delivered via the messaging_postbacks webhook (required when type is postback) | [optional] |
| phone | string | Phone number, e.g. +14155551234 (required when type is phone; Facebook only) | [optional] |