未捕获的TypeError:无法读取未定义vue的属性“”$bvModal“”

npm install vue bootstrap-vue bootstrap

import Vue from 'vue'
import BootstrapVue from 'bootstrap-vue'

import 'bootstrap/dist/css/bootstrap.css'
import 'bootstrap-vue/dist/bootstrap-vue.css'

Vue.use(BootstrapVue)

<template>
  <div>
    <button @click="openModal">打开模态框</button>
    <b-modal v-model="modalOpen">模态框内容</b-modal>
  </div>
</template>

<script>
export default {
  data() {
    return {
      modalOpen: false
    }
  },
  methods: {
    openModal() {
      this.modalOpen = true
    }
  }
}
</script>