使用dialogflow将多个参数写入firestore数据库

我创建了一个dialogflow代理来注册来自用户的一些信息，因为我需要为每个用户将这些答案写为相同的文档，但是我编写的代码是将每个答案写到单个文档中，而不是将所有答案都写成一个单独的文档，日志没有显示任何错误，所以我想这是我无法识别的逻辑问题...

index.js：

'use strict';

const functions = require('firebase-functions');
const {WebhookClient} = require('dialogflow-fulfillment');
const {Card, Suggestion} = require('dialogflow-fulfillment');
const admin = require('firebase-admin');
admin.initializeApp();
const db = admin.firestore();

process.env.DEBUG = 'dialogflow:debug'; // enables lib debugging statements

exports.dialogflowFirebaseFulfillment = functions.https.onRequest((request, response) => {
  const agent = new WebhookClient({ request, response });
  console.log('Dialogflow Request headers: ' + JSON.stringify(request.headers));
  console.log('Dialogflow Request body: ' + JSON.stringify(request.body));

  function cadastroHandler(agent) {
    let nome = agent.parameters.nome ;
    db.collection("cadastros").add({ nome: nome });

    let estado = agent.parameters.estado ;
    db.collection("cadastros").add({ estado: estado });

    let cidade = agent.parameters.cidade ;
    db.collection("cadastros").add({ cidade: cidade });

    let coord = agent.parameters.coord ;
    db.collection("cadastros").add({ coord: coord });

    let wppcoord = agent.parameters.wppcoord ;
    db.collection("cadastros").add({ wppcoord: wppcoord });

    let emailcoord = agent.parameters.emailcoord ;
    db.collection("cadastros").add({ emailcoord: emailcoord });

    let area = agent.parameters.area ;
    db.collection("cadastros").add({ area: area });

    agent.add(`cadastro concluido`);
  }

  function fallback(agent) {
    agent.add(`I didn't understand`);
    agent.add(`I'm sorry, can you try again?`);
  }


  let intentMap = new Map();
  intentMap.set('cadastro', cadastroHandler);
  intentMap.set('Default Fallback Intent', fallback);
  // intentMap.set('your intent name here', yourFunctionHandler);
  // intentMap.set('your intent name here', googleAssistantHandler);
  agent.handleRequest(intentMap);
});

以相同的“ cadastro”意图向用户依次询问每个参数，并作为单独的参数登录