在回调函数的 payload 中添加任务令牌。以下是示例代码：

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

const stepfunctions = new AWS.StepFunctions();

exports.handler = (event, context, callback) => {  
  const params = {
    output: JSON.stringify({ message: 'Task completed successfully.' }),
    taskToken: event.token // 设置任务令牌
  };
  
  stepfunctions.sendTaskSuccess(params, (err, data) => {
    if(err){
        console.log(err, err.stack);
        callback('Error: Sending task success failed.');
    }else{
        callback(null, 'Success');
    }
  });
};