add whatsapp to flex
curl -X POST "https://flex-api.twilio.com/v1/FlexFlows" \
--data-urlencode "ChannelType=whatsapp" \
--data-urlencode "Enabled=true" \
--data-urlencode "IntegrationType=studio" \
--data-urlencode "ContactIdentity=whatsapp:+xxxx" \
--data-urlencode "FriendlyName=Flex WhatsApp FlexFlow" \
--data-urlencode "Integration.FlowSid=FWxx" \
--data-urlencode "ChatServiceSid=ISxx" \
-u ACxx:yourAuthToken