How to dynamically show data of any table on dashboard using content block Jelly ServiceNow?

Client Callable Script Include:
 var BillingInfoUtil = Class.create();
BillingInfoUtil.prototype = Object.extendsObject(AbstractAjaxProcessor, {
   getBillingInfo: function(){
  var taskType = this.getParameter('sysparm_task_type');
  gs.log("Task Type: " + taskType, "Select EX")
  var gr = new GlideRecord("incident");
  //this gliderecord setup is assuming you're expecting one record exists that meets the
  //criteria. Adjust if necessary
  gr.get(taskType);
  var fields = ['number','short_description','state']
        var bu = {};
  if (gr.getUniqueValue()){
   //this is an assumption. You'll need to determine what your needs are;
   fields.forEach(function(field){
    bu[field] = gr.getValue(field)
   })
      }
     return JSON.stringify([bu]);
    },
     type: 'BillingInfoUtil'
});
  Dynamic content: Incidentdata
 <?xml version="1.0" encoding="utf-8" ?>
<j:jelly trim="false" xmlns:j="jelly:core" xmlns:g="glide" xmlns:j2="null" xmlns:g2="null">
 <g:evaluate var="jvar_tasktypes" object="true" jelly="true">
  // Changed to GlideRecord for demo purpose as I don't have the same tables or setup as you
  var objs = [];
  var gr= new GlideRecord('incident');
  gr.groupBy('number');
  gr.setLimit(5);
  gr.query();
  while(gr.next()){
  objs.push({'sys_id': gr.getValue('sys_id'),'number':gr.getDisplayValue('number')});
  }
  objs;
 </g:evaluate>
 <div class="container">
  <div class="col-md-3">
   <div class="panel-body">
    <h4>Select an Incident</h4>
    <select id='filter_task_type' class='select2-search form-control'  onchange='filterTaskType()'>
     <option value="">--None--</option>
     <j:forEach var="jvar_tasktype" items="${jvar_tasktypes}">
      <option value="${jvar_tasktype.sys_id}">${jvar_tasktype.number}</option>       
     </j:forEach>
    </select>  
   </div>
  </div>
  <div class="col-md-9">
   <div class="panel-body">
    <h3>Incident Details</h3>
    <div id="incDetails">
     <div class="list-group"></div>
    </div>
   </div>
  </div>
 </div>
 <script>
  function filterTaskType(){
   var container = document.querySelector('.container');
   var taskType = container.querySelector('#filter_task_type').value;
      var incDetails = container.querySelector('.list-group');
        //Here is where the GlideAjax comes in instead of g:evaluate
      var ga = new GlideAjax('BillingInfoUtil');
   ga.addParam('sysparm_name', 'getBillingInfo');
   ga.addParam('sysparm_task_type', taskType);
   ga.getXML(callback);
       function callback(response) {
     var result = response.responseXML.documentElement.getAttribute("answer");
        var details = JSON.parse(result);
        var keys = Object.keys(details[0]);
        var html = [];
        keys.forEach(function(key){
     var label = key.toUpperCase().replace("_", " ");
           var text = details[0][key];
           html.push('<div class="list-group-item"><h4 class="list-group-item-heading">'+ label + '</h4>');
     html.push('<p class="list-group-item-text">' + text + '</p></div>');
     });
         incDetails.innerHTML = html.join("");
         }
   }
  </script>
 </j:jelly>