Places a voice or video call. Limited to 10 per minute and 100 per hour per instance; the slot is taken before the media URLs are fetched, so a bad audioUrl or videoUrl still spends one. With waitForAnswer (default true) the response tells whether the callee picked up within answerTimeout; on timeout the instance hangs up. Optional audioUrl/imageUrl/videoUrl play after the call was answered; hangupAfterSeconds ends the call and counts from the moment the call connects, not from this response, so a call can last up to the 10 second connection wait plus hangupAfterSeconds. Over the limit the answer is data.status: error with message: too many calls, an explanation and retryAfter in seconds. Note: This endpoint is currently in beta and may change without notice.