如何在Vue.js中包含外部Vue脚本

<template>
  <div>
    <external-component></external-component>
  </div>
</template>

<script>
import ExternalComponent from './ExternalComponent.vue';

export default {
  components: {
    ExternalComponent
  }
}
</script>

<template>
  <div>
    <component :is="externalComponent"></component>
  </div>
</template>

<script>
import ExternalComponent from './ExternalComponent.vue';

export default {
  data() {
    return {
      externalComponent: ExternalComponent
    }
  }
}
</script>

<template>
  <div>
    <button @click="externalMethod">Click me</button>
  </div>
</template>

<script>
import ExternalMixin from './ExternalMixin.js';

export default {
  mixins: [ExternalMixin]
}
</script>