How do I add more than one custom field to event editor?

onPopupOpen(args: PopupOpenEventArgs): void {
  if (args.type === 'Editor') {
    // Create required custom elements in initial time
    if (!args.element.querySelector('.custom-field-row')) {
      let row: HTMLElement = createElement('div', {className: 'custom-field-row'});
      let formElement: HTMLElement = args.element.querySelector('.e-schedule-form');
      formElement.firstChild.insertBefore(row, args.element.querySelector('.e-title-location-row'));
      let container: HTMLElement = createElement('div', {className: 'custom-field-container'});
      let inputEle: HTMLInputElement = createElement('input', {
        className: 'e-field', attrs: {name: 'Client'}
      }) as HTMLInputElement;
      container.appendChild(inputEle);
      row.appendChild(container);
      let dropDownList: DropDownList = new DropDownList({
        dataSource: [
          {text: 'Person1', value: 'Person1'},
          {text: 'Person2', value: 'Person2'},
          {text: 'Person3', value: 'Person3'},
          {text: 'Person4', value: 'Person4'}
        ],
        fields: {text: 'text', value: 'value'},
        value: (<{ [key: string]: Object }>(args.data)).Client as string,
        floatLabelType: 'Always', placeholder: 'Client'
      });
      dropDownList.appendTo(inputEle);
      inputEle.setAttribute('name', 'Client');
     
    }

  }
  }

(sorry for posting this in two forum parts as I didnt know where to post it exactly)