Peer-group parsing error

{
    "errors": {
        "error": [
            {
                "error-type": "protocol",
                "error-tag": "malformed-message",
                "error-message": "Error parsing input: Child \"peer-group\" was not found in parent schema node \"(urn:opendaylight:params:xml:ns:yang:bgp:openconfig-extensions?revision=2018-03-21)peer-groups\"",
                "error-info": "Child \"peer-group\" was not found in parent schema node \"(urn:opendaylight:params:xml:ns:yang:bgp:openconfig-extensions?revision=2018-03-21)peer-groups\""
            }
        ]
    }
}