Subscribed webhook for event filter '/restapi/v1.0/glip/tasks' have not receive events

So instead of asking such a question, ask how to get Team Messaging Task notification events.

In fact, you just need to subscribe for the ''/restapi/v1.0/glip/posts' event and detect the type in the event payload. E.g.

{
  "id": "37742841397252",
  "groupId": "1152743292930",
  "type": "TextMessage",
  ...
  "attachments": [
    {
      ...
      "section": "Delete",
      "status": "Pending",
      "subject": "Check and clean up",
      "type": "Task"
    }
  ],
  ...
  "eventType": "PostAdded"
}