sendChannelMessage
inline suspend fun ChimeSdkMessagingClient.sendChannelMessage(crossinline block: SendChannelMessageRequest.Builder.() -> Unit): SendChannelMessageResponse
Sends a message to a particular channel that the member is a part of.
The x-amz-chime-bearer request header is mandatory. Use the ARN of the AppInstanceUser or AppInstanceBot that makes the API call as the value in the header.
Also, STANDARD messages can be up to 4KB in size and contain metadata. Metadata is arbitrary, and you can use it in a variety of ways, such as containing a link to an attachment.
CONTROL messages are limited to 30 bytes and do not contain metadata.