Amazon web services AWS API网关，EventBridge:指定的选择表达式无效

我尝试将Lambda authorizer上下文属性映射到事件，但在控制台中保存配置时会引发错误

映射模板：

{
  "payload": {
    "data": "hello"
  },
  "authorizer": {
    "id": "$context.authorizer.id"
  }
}

错误通知消息：

Invalid selection expression specified: Validation Result: warnings : [], errors : [Invalid source: {"payload": { "data": "hello"}, "authorizer": {"id": "$context.authorizer.id"} } specified for destination: Detail]