问import 需要指定文件扩展名js？

{
  "name": "src",
  "version": "1.0.0",
  "dependencies": {
  },
  "type": "module",
  "scripts": {
    "start": "nodemon --experimental-modules --es-module-specifier-resolution=node te1.js"
  }
}

  function ss(x, y) {
    return x+y;
}

export  default  ss;

 import aa from './aa ';
//import {math} from 'math';
  var he =aa(1,2);
 console.log("dddd");
 console.log(he);

 import aa from './aa.js ';
//import {math} from 'math';
  var he =aa(1,2);
 console.log("dddd");
 console.log(he);