FHIR Data not return content

Hi,

I found an issue while fetching records from FHIR DB, I am getting below error thou FHIR repository have the records with the corresponding id

{

    "resourceType": "OperationOutcome",

    "issue": [

        {

            "severity": "error",

            "code": "not-found",

            "diagnostics": "<HSFHIRErr>ResourceNotFound",

            "details": {

                "text": "No resource with type 'Appointment' and id '21'"

            }

        }

    ]

}