vue_script.ts

import Vue from 'vue'
import axios from 'axios'

export default Vue.extend({
    name: 'HelloWorld',

    data () {
        return {
            msg: ''
        }
    },

    mounted () {
        axios.get(`http://localhost:3000`)
            .then(response => {
                this.msg = response.data['message']
            })
    }
})