webhookHeaders property

This field can be used to pass HTTP headers for a webhook call.

These headers will be sent to webhook along with the headers that have been configured through the Dialogflow web console. The headers defined within this field will overwrite the headers configured through the Dialogflow console if there is a conflict. Header names are case-insensitive. Google's specified headers are not allowed. Including: "Host", "Content-Length", "Connection", "From", "User-Agent", "Accept-Encoding", "If-Modified-Since", "If-None-Match", "X-Forwarded-For", etc.