Combined voice and SMS alert

Send an alert that use both voice and SMS. Specify the alert types, content, sender and recipient list (which can be the same or different for both).

{
    "version": "latest",
    "apiKey": "abcdefghijklmnopqrstuvwxyz",
    "clientRef": "abcd-efgh",
    "alert": [
        {
            "alertType": "sms",
            "tag": "t1",
            "content": "This is an SMS 1",
            "contentEncoding": "utf8",
            "sender": "+447777100100",
            "recipientList": "+447777100100"
        },
        {
            "alertType": "call",
            "sender": "+447777100100",
            "recipients": [
                "+447777100100",
                "+447777100100",
                "+447777100100"
            ],
            "tag": "t1",
            "voiceFormat": "mp3",
            "contentEncoding": "base64",
            "content": "UklGRgi3.................w=="
        }
    ]
}