The way I have my map setup is with the following:

I am creating a Bing map, and collecting the session key

    <script type='text/javascript'>

        var map, sessionKey;

        function GetMap() {
            map = new Microsoft.Maps.Map('#myMap');

            //Get a session key from the map and use with the REST services to make requests non-billable transactions.
            map.getCredentials(function (c) {
                sessionKey = c;
            });
        }
    </script>


    <script type='text/javascript' src='https://www.bing.com/api/maps/mapcontrol?callback=GetMap&key=[MY_BING_API_KEY]' async="async" defer="defer"></script>

Then I use that session key with the igMap

        $(chartID).igMap({
            backgroundContent: {
                type: "bing",
                key: sessionKey,
                bingUrl: "https://dev.virtualearth.net/rest/v1/imagery/metadata/",
                imagerySet: "AerialWithLabels"
            }
        })

Is there anyway for me to know if the session key is working as intended?