index.js

import apiFetch from '@wordpress/api-fetch';
import {addQueryArgs} from '@wordpress/url';

import {getCurrentPost} = wp.data.select('core/editor');
const api_path = '/wp/v2/pdf_template/'; //this is the slug of rest_endpoint set inside the register_post_type


function TemplateList() {

  function handleOnClick(template) {

    const currentPost = getCurrentPost();
    var newPost = currentPost;
    newPost.content = template.content;
    
    const query = {
      ywraq_edit_pdf_template: true,
    };
    
     apiFetch({
       //adding the id inside the api_path the post will be update otherwise a new post will be created and the new object passed in data (then)
      path: addQueryArgs(api_path + currentPost.id, query), 
      data: Object.assign({}, newPost),
      method: 'POST',
    }).then((data) => {
      console.log(data);
      wp.data.dispatch('core/editor').editPost( {content: template.content }); //change the current post inside the wp.data
      wp.data.dispatch( 'core/block-editor' ).resetBlocks( wp.blocks.parse( template.content ) );  //render the block of the new content inside the editor
    }).catch((error) => {
      console.log(error);
    });
    
  }
  
    return (
      <div onClick={() => handleOnClick(template1)}>{template1.id}</div>
  );
}

export default TemplateList;