无法使用 vditor.getValue();

根据教程在网页加入了

<script src="https://unpkg.com/vue"></script>
<script src="https://unpkg.com/marked@0.3.6"></script>
<script src="https://unpkg.com/lodash@4.16.0"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/vditor/dist/index.css" />
<script src="https://cdn.jsdelivr.net/npm/vditor/dist/index.min.js"></script>

以及 script 标签里加入

new Vue({
  el: '#app',
  data: {
    contentEditor: '',
  },
  mounted () {
    this.contentEditor = new Vditor('vditor', {
      height: 360,
      toolbarConfig: {
        pin: true,
      },
      cache: {
        enable: false,
      },
      after: () => {
        this.contentEditor.setValue('hello, Vditor + Vue!')
      },
    })
  },
})

在网页上能够正常使用编辑器，但是当我在调试台使用 vditor.getValue();时总是报错 vditor.getValue is not a function