I am trying to create an action framework which alerts community users that there is a problem with a document. This email should come from the email address of the agent who owns the account, which are all registered as org-wide email addresses. The action framework requires a 'sender type' parameter to send as anything other than the current user, however any value I insert here results in a Bad Request error on fire. Digging deeper into the error message reveals that the problem is an "INVALID_ARGUMENT_TYPE". Does anyone have any idea what a valid argument for this field would be?