1. app.config.globalProperties Global Property

// main.js Regist
import { createApp } from 'vue'
import axios from 'axios'
 
 
const app = createApp({
  created() {
    console.log(this.$axios)
  }
})
app.config.globalProperties.$axios = axios
app.mount('#root')

// App.vue Usage
<script setup>
import {getCurrentInstance} from 'vue'
const { proxy } = getCurrentInstance(); //获取公用方法proxy.$axios
const {$axios}=proxy
console.log($axios)
</script>

2. mixin

   import { createApp} from 'vue'
   import axios from 'axios'
    
   const app = createApp({
     created() {
       console.log(this.$axios)
     }
   })
   app.mixin({
     methods: {
       $axios: axios
     }
   })
   app.mount('#root')

3. provide, inject

   import { createApp } from 'vue'
   import axios from 'axios'
    
    
   const app = createApp({
     inject: ['$axios'],
     created() {
       console.log(this.$axios)
     }
   })
   app.provide('$axios', axios)
   app.mount('#root')