Customizing the contextPad with html content

Hi Team, I am very new to BPMN library and any help is greatly appreciated. The workflow I am trying to implement is like the below.

Screenshot from 2023-06-12 10-50-13

here is my code

if (element.type === 'bpmn:StartEvent') {
   return {
     'customAction': {
       group: 'model',
       className: 'icon-custom ami-task',
       title: translate('ami-task'),
       action: {
         click: appendTask,
         dragstart: appendTaskStart


the problem is when i use html action click and drag start not work any idea how I can Customizing contextPad with html css

thanks all

What exactly does not work? You extend things in the correct way as it looks like.