Message Callback Schema
| Name | Type | Description | Notes |
|---|---|---|---|
| Time | DateTime | ||
| Type | CallbackTypeEnum | ||
| To | string | ||
| Description | string | A detailed description of the event described by the callback. | |
| Message | MessageCallbackMessage | ||
| ErrorCode | int? | Optional error code, applicable only when type is `message-failed`. | [optional] |