Why can't the template of vue component be displayed?

in writing vue component encountered a problem, that is, the template can not be displayed, has not reported an error ~ tried a lot of ways still can not show, collapse, come here to help seniors! Thank you very much!

<div id="app">
    {{a}}   //1
  </div>
  <template id="aaa">
   <h3 @click="show()">{{msg}}</h3> //
  </template>
const vm = new Vue({
        el: "-sharpapp",
        data: {
          a: 1
        },
        components: {
          //
          "my-aaa": {
            data() {
              return {
                msg: "welcome"
              }
            },
            methods: {
              show() {
                this.msg = "woof"
              }
            },
            template: "-sharpaaa"
          },
        }
      })
Mar.04,2021

{{msg}}</h3> //
</template>

you defined the component, but did not reference it on the node of the vm. So it didn't show up

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