Документация: https://ssr.vuejs.org/guide/#installation
Пример:
// Step 1: Create a Vue instance
const Vue = require('vue')
const app = new Vue({
template: `<div>Hello World</div>`
})
// Step 2: Create a renderer
const renderer = require('vue-server-renderer').createRenderer()
// Step 3: Render the Vue instance to HTML
renderer.renderToString(app, (err, html) => {
if (err) throw err
console.log(html)
// => <div data-server-rendered="true">Hello World</div>
})
// in 2.5.0+, returns a Promise if no callback is passed:
renderer.renderToString(app).then(html => {
console.log(html)
}).catch(err => {
console.error(err)
})