使用 AWS Cognito SDK 获取一个 AWS Cognito IdentityID 和 Identity PoolID。以下是 Node.js 示例代码：

const AWS = require('aws-sdk');
AWS.config.region = 'us-west-2';

// 初始化 AWS Cognito SDK
const cognitoidentity = new AWS.CognitoIdentity();
const poolId = 'YOUR_COGNITO_POOL_ID';
const params = {
   IdentityPoolId: poolId
};

// 获取 AWS Cognito IdentityID 和 Identity PoolID
cognitoidentity.getId(params, function(err, data) {
   if (err) {
      console.log(err, err.stack);
   } else {
      console.log(data);
   }
});

确保将 "YOUR_COGNITO_POOL_ID" 替换为你的 AWS Cognito Identity PoolID。这段代码将返回类似以下的 JSON 数据：

{
   "IdentityId": "us-west-2:12345678-1234-1234-1234-123456789012",
   "ResponseMetadata": {
      "RequestId": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
      "HTTPStatusCode": 200,
      "HTTPHeaders": {
         "date": "Tue, 19 May 2020 00:00:00 GMT",
         "content-type": "application/x-amz-json-1.1",
         "content-length": "63",
         "connection": "keep-alive",
         "x-amzn-requestid": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
      },
      "RetryAttempts": 0
   }
}

你现在可以使用返回的 IdentityID 和 Identity PoolID 进行 AWS Cognito 认证了。