Node.js 使用 Forms API 进行批量更新时生成 itemId

请问在生成Itemid时有哪些约束条件.我为表单中的每一项生成唯一的ItemID，但API总是告诉我无效的ID.

https://developers.google.com/forms/api/reference/rest/v1/forms#Item个

拜托，我需要你的帮助

{
    "includeFormInResponse": false,
    "requests":     [
        {
            "createItem": {
                "item": {
                    "itemId": "4e637fjc",
                    "description": "First Name",
                    "questionItem": {
                        "question": {
                            "textQuestion": {
                                "paragraph": false
                            },
                            "required": true
                        }
                    }
                },
                "location": {
                    "index": 0
                }
            }
        },
        {
            "createItem": {
                "item": {
                    "itemId": "njyf3izr",
                    "description": "Middle Name",
                    "questionItem": {
                        "question": {
                            "textQuestion": {
                                "paragraph": false
                            },
                            "required": true
                        }
                    }
                },
                "location": {
                    "index": 1
                }
            }
        },
    }
]