API addDiscovery doesn't work

API addDiscovery doesn't work

Dear experts,

I tried to use addDiscovery API. Request looks like this https://servername:8061/api/json/ncmsettings/addDiscovery?apiKey=...&TIMEOUT=300&RETRIES=1&DISC_TYPE=IPRange&HOST=ru0994-flr10-cx-sw&START_ADDR=192.168.1.1&END_ADDR=192.168.1.1

Results is
<body>
    <h1>HTTP Status 404 – Not Found</h1>
    <hr class="line" />
    <p><b>Type</b> Status Report</p>
    <p><b>Message</b> Not Found</p>
    <p><b>Description</b> The origin server did not find a current representation for the target resource or is not
        willing to disclose that one exists.</p>


Please advise, what's wrong?

Thank you