Troubleshooting of WikiData API

How to fix the error Unrecognized value for parameter "props": sitelinks/zhwiki

When I request the API url: https://www.wikidata.org/w/api.php?action=wbgetentities&format=json&props=labels%7Csitelinks/zhwiki&ids=Q21007575&languages=zh , I met the error message:

{
    "warnings": {
        "wbgetentities": {
            "*": "Unrecognized value for parameter \"props\": sitelinks/zhwiki"
        }
    },
    "entities": {
        "Q21007575": {
            "type": "item",
            "id": "Q21007575",
            "labels": {}
        }
    },
    "success": 1
}

Root cause

• The page did not have the property sitelinks/zhwiki

Solution

• You can change the URL parameter sitelinks/zhwiki to sitelinks e.g. https://www.wikidata.org/w/api.php?action=wbgetentities&format=json&props=labels%7Csitelinks&ids=Q21007575&languages=zh