调用Google Optimisation API遇fieldViolation错误，请求符合文档规范

我尝试向Google优化API发送请求，但收到fieldViolation错误。已确认请求和文档中的多个示例、字段规范完全匹配，将值改为数字后仍报错，仅错误信息里的引号会消失。

发送的请求JSON： #

"shipments": [
  {
    "displayName": "private",
    "pickups": [
      {
        "arrivalLocation": {
          "latitude": 具体数值,
          "longitude": 具体数值
        },
        "tags": [
          "some strings"
        ],
        "timeWindows": [
          {
            "startTime": "2023-09-04T01:30:00.000Z",
            "endTime": "2023-09-04T03:50:00.000Z"
          }
        ],
        "duration": "10s",
        "cost": 0,
        "loadDemands": {
          "pallet_count": {
            "amount": "2"
          }
        }
      }
    ]
  }
]

返回的验证错误： #

"fieldViolations": [
{
  "field": "model.shipments[0].load_demands[0].value",
  "description": "Invalid value at 'model.shipments[0].load_demands[0].value' (type.googleapis.com/google.cloud.optimization.v1.Shipment.Load), \"2\""
},
{
  "field": "model.shipments[1].load_demands[0].value",
  "description": "Invalid value at 'model.shipments[1].load_demands[0].value' (type.googleapis.com/google.cloud.optimization.v1.Shipment.Load), \"1\""
},
{
  "field": "model.shipments[2].load_demands[0].value",
  "description": "Invalid value at 'model.shipments[2].load_demands[0].value' (type.googleapis.com/google.cloud.optimization.v1.Shipment.Load), \"1\""
}
]

参考文档： #

• Load 对象文档
• loadDemands 字段文档
• 完整示例文档（请求结构与我的一致）

内容的提问来源于stack exchange，提问作者Matt