vue3.x 关于引入第三方组件报错

main.js之前的写法

import Vue from'vue'
import App from'./App.vue'
import router from'./router/index'
import store from'./store'

import'element-ui/lib/theme-chalk/index.css';
import ElementUI from'element-ui';

Vue.use(ElementUI);
newVue({
  router,
  store,
  render: h=>h(App),}).$mount('#app')

新的写法

import{ createApp} from'vue'
import App from'./App.vue'
import router from'./router'
import store from'./store'

import'element-plus/lib/theme-chalk/index.css';
import ElementPlus from'element-plus';const app=createApp(App)
app.use(ElementPlus)
app.use(store).use(router).mount('#app')