how can i store data in json file Continuous for discord js

I want to take the message information from the user and save it in a JSON file and this data is constantly added, but with the following code, this data is constantly replaced.
and I don’t replace data I want to add data
this is my code :

const fs = require("fs");
const { Client, Intents } = require("discord.js");

const client = new Client({
  intents: [Intents.FLAGS.GUILDS, Intents.FLAGS.GUILD_MESSAGES],
});
const now = new Date();
const obj = {
  table: [],
};
let confirm = false;
const { badWords } = require("../badWordList.json");
client.on("message", async (message) => {
  if (message.author.bot) return;
  for (let i = 0; i < badWords.length; i++) {
    if (message.content.toLowerCase().includes(badWords[i].toLowerCase()))
      confirm = true;
  }
  if (confirm) {
    obj.table.push({
      name: message.author.username,
      date: `${now.getFullYear()}/${now.getMonth()}/${now.getDate()}`,
      message: message.channel.messages.channel.lastMessage.cleanContent,
    });
    fs.writeFile("myjsonfile.json", JSON.stringify(obj), function (err) {
      if (err) throw err;
      console.log("complete");
    });
  }
});