vue3 使用axios 会报错“Uncaught TypeError: Cannot read property ‘get‘ of undefined”

原因是在main中，需要把“app.use(VueAxios, axios)”放在“app.mount('#app')”之前，如代码：

import { createApp } from 'vue'
import App from './App.vue'
import axios from 'axios'
import VueAxios from 'vue-axios'
import installElementPlus from './plugins/element.js'

const app = createApp(App)
installElementPlus(app)
app.use(VueAxios, axios)
app.mount('#app')

记录一下。