Marks an inbound message as read and displays a typing indicator so the WhatsApp user knows you are preparing a response. Messages marked as read display two blue check marks alongside their timestamp. The typing indicator is dismissed once you respond, or after 25 seconds, whichever comes first.

Marking a message as read also marks earlier messages in the conversation as read. Repeating this request sends another typing-indicator request and refreshes the indicator; this endpoint does not provide an idempotency key.

A successful request returns WhatsappInboundMessageTypingResponse. Errors reuse the standard ErrorResponse.