uniapp vue3 "default" is not exported by

uniapp vue3 does not have a default export named "default". In Vue 3, the way to import and use the Vue instance has changed.

Instead of using a default export, you can import the Vue instance from the "vue" package like this:

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

createApp(App).mount('#app')

In this example, we use the `createApp` function from the "vue" package to create a new Vue app instance. We then mount the app to the element with the id "app" in the HTML file.

Make sure you have the "vue" package installed in your project before using Vue 3 in Uniapp. You can install it with the following command:

npm install vue@next

Please note that Uniapp currently supports Vue 2 by default, so you need to manually configure it to use Vue 3.