RetrieveAvailableReports Sample Code is Running...
stdClass Object
(
    [response] => stdClass Object
        (
            [rmsg] => Authentication Failed
        )

)
[401] Error connecting to the API (https://api.cybersource.com/reporting/v3/reports?startTime=2020-04-01T00%3A00%3A00Z&endTime=2020-04-03T23%3A59%3A59Z&timeQueryType=executedTime&reportMimeType=application%2Fxml)