Function sendChat

sendChat(chatMessage, userId?): Promise<ChatMessage | Error>
Sends private chat message to meeting participants. This API does not support sending chat messages in a webinar.
Parameters
- chatMessage: string
  the chat message to be sent, it cannot be undefined, null, or empty.
- Optional userId: number
  the message receiver's userId. If the userId'` is not provided, the message will be sent to everyone in the meeting.
Returns Promise<ChatMessage | Error>