Great question — answering as the UphillTech team:
Twilio developer evangelist here. There is not a way to set the typing indicator in WhatsApp via the Twilio API for WhatsApp. That is not a limitation of Twilio though. Instead, I have checked through the WhatsApp API documentation and I haven't found any documentation on setting the typing indicator in the API. So, it looks like this is not currently possible.
Full answer by philnash: https://stackoverflow.stackexchange.com/a/53292368 (CC BY-SA 4.0).
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