Koa cannot get ctx.request.body, through bodyparser. Must it be converted through json?

Front-end axios

this.$axios({
                method:"post",
                url:"/api/login",
                data : {         //json
                  name : this.name,
                  password: this.password
                }

koa

const Koa = require("koa");
const app = new Koa();
const bodyParser = require("koa-bodyparser");
const router = require("./router/main")

app.use(bodyParser()) //POST 

app.use(router.routes());

app.use(router.allowedMethods())  //

app.listen(3000);

user.post("/login",async(ctx)=>{
  console.log("req.body = "+JSON.stringify(ctx.request.body))
  // {"name":"hqb","password":"123"}

  console.log("req.body = "+ctx.request.body)
   //[object Object]

  ctx.body = "LOGIN OK"