"The destination is disabled" when sending SMS

Getting the below error when sending SMS:

    com.ringcentral.RestException: HTTP Response
    =============
    status code: 403
    Server: nginx
    Date: Thu, 14 Apr 2022 20:09:34 GMT
    Content-Type: application/json;charset=utf-8
    Content-Length: 175
    Connection: keep-alive
    RCRequestId: cd7122ca-bc2e-11ec-966a-0050568cbe06
    RoutingKey: SJC01P18PAS08
    Content-Language: en-US
    X-Rate-Limit-Group: sms
    X-Rate-Limit-Limit: 60
    X-Rate-Limit-Remaining: 59
    X-Rate-Limit-Window: 60
    
    {
      "errorCode" : "MSG-386",
      "message" : "The destination is disabled.",
      "errors" : [ {
        "errorCode" : "MSG-386",
        "message" : "The destination is disabled."
      } ]
    }

HTTP Request
============
HTTP POST https://platform.ringcentral.com/restapi/v1.0/account/~/extension/~/sms

Please help in finding the root cause!