Using ref as pdf-content does not print layout html report

[Amkha]

Describe the bug
When using ref in div tage, it print only when the data is available. Whithout data just print blank page since data_pdf is null.
the data_pdf is content html from parent component referring by ref in div tag. below is my code

1. Parent component:

<!-- <template>
  <v-container>
    <div ref="section_trial_balance" id="tblData">
           <table>
                        <tr class="pa-2">
                            <th style="width: 500px; text-align: center;">Description</th>
                        </tr>
                        <tr class="pa-2 tr0">
                            <td class="pa-2 td0">{{0}}</td>
                        </tr>
            <table>
   </div> 
<SideBarRight @clicked="onClickChild" :fromdate="from_date" :todate="to_date" :repno="rep_no" :data_excel="t_balance" :tableId="'tblData'" :data_pdf="this.$refs.section_trial_balance"></SideBarRight>
</v-container>
</template>   -->
data: () => ({
           trial_balance: []
})

3. Child component(SideBar-Right):

<template>
       <div>
        <vue-html2pdf
          :show-layout="false"
          :float-layout="false"
          :enable-download="true"
          :preview-modal="true"
          :paginate-elements-by-height="1100"
          :pdf-quality="2"
          :manual-pagination="true"
          pdf-format="a4"
          pdf-orientation="portrait"
          pdf-content-width="800px"
          @hasStartedGeneration="hasStartedGeneration()"
          @hasGenerated="hasGenerated($event)"
          ref="html2Pdf"
          filename="mcfin_filename"
          <section slot="pdf-content">
              <v-container>
                     <v-card v-html="html_doc"></v-card>
               </v-container>
          </section>
        </vue-html2pdf>
      </div>
</template>
import VueHtml2pdf from 'vue-html2pdf'
  export default {
    name: 'side-bar-right',
    components: {
       VueHtml2pdf
    },
    props: ['data_excel', 'tableId','data_pdf','repno', 'to_date'],
    data () {
      return {
        pdf_filename: '',
        html_doc: '',
        }
     }
methods: {
      exportPdf(){
        console.log("PDF:", this.data_pdf)      // this gives null when no data generated and not print layout <table>
        this.html_doc = this.data_pdf.outerHTML 
        this.$refs.html2Pdf.generatePdf()
      },
}

jason.package:
"sass": "^1.56.1",
"sass-loader": "^8.0.2",
"vue": "^2.6.12",
"vue-loader": "^15.9.5",
"vue-template-compiler": "^2.6.10"
"vue-html2pdf": "^1.8.0",
"vuetify": "^2.6.12",
"vue-router": "^3.5.1",
"vuex": "^3.6.2",

And handle event gives some errors
Please help !!!!

[Amkha]

not visible either here....