// POST /admin/webhooks/
{
    "webhooks": [{
            "event": "post.added",
            "target_url": "https://example.com/hook/"
    }]
}

{
    "webhooks": [
        {
            "id": "5f04028cc9b839282b0eb5e3",
            "event": "post.added",
            "target_url": "https://example.com/hook/",
            "name": null,
            "secret": null,
            "api_version": "v6",
            "integration_id": "5c739b7c8a59a6c8ddc164a1",
            "status": "available",
            "last_triggered_at": null,
            "last_triggered_status": null,
            "last_triggered_error": null,
            "created_at": "2020-07-07T05:05:16.000Z",
            "updated_at": "2020-09-15T04:01:07.643Z"
        }
    ]
}

POST /admin/webhooks/
Required fields: event, target_url Conditionally required field: integration_id - required if request is done using user authentication Optional fields: name, secret, api_version Example to create a webhook using token authenticated request. 
// POST /admin/webhooks/
{
    "webhooks": [{
            "event": "post.added",
            "target_url": "https://example.com/hook/"
    }]
}
When creating a webhook through user authenticated request, minimal payload would look like following: 
// POST /admin/webhooks/
{
    "webhooks": [{
            "event": "post.added",
            "target_url": "https://example.com/hook/",
            "integration_id": "5c739b7c8a59a6c8ddc164a1"
    }]
}
and example response for both requests would be: 
{
    "webhooks": [
        {
            "id": "5f04028cc9b839282b0eb5e3",
            "event": "post.added",
            "target_url": "https://example.com/hook/",
            "name": null,
            "secret": null,
            "api_version": "v6",
            "integration_id": "5c739b7c8a59a6c8ddc164a1",
            "status": "available",
            "last_triggered_at": null,
            "last_triggered_status": null,
            "last_triggered_error": null,
            "created_at": "2020-07-07T05:05:16.000Z",
            "updated_at": "2020-09-15T04:01:07.643Z"
        }
    ]
}