vue3+vant4+ts出现页面空白？甚至在App.vue的＜template＞＜/template＞中随便输入都无法显示？

踩坑：我在设置路由时将app.mount('#app');放到了后路由后面出现了也面无法加载

import * as VueRouter from 'vue-router';
import routes from "./config/route.ts";
const  app=createApp(App);
app.use(NavBar);
app.use(Button);
app.use(Icon);
app.use(Tabbar);
app.use(TabbarItem);
app.mount('#app');
const router = VueRouter.createRouter({
    history: VueRouter.createMemoryHistory(),
    routes,
})
app.use(router);