How to create webhook for confluence server 7.2?

[AppConnect]

I am following documentation
https://docs.atlassian.com/ConfluenceServer/rest/7.2.0/
I followed all steps give in a Documents for create a webhook.
I am getting error in response from a server with status code 501 and in body I got,

{

    "statusCode": 501,

    "data": {

        "authorized": false,

        "valid": true,

        "allowedInReadOnlyMode": true,

        "errors": [],

        "successful": false

    },

    "message": "Webhooks are not yet supported",

    "reason": "Not Implemented"

}
What things I need to do for creating webhook successful?

[Rachel Robins]

It's not possible to register a webhook in Confluence 7.2.  We've been working on adding webhook support, and the REST documentation was published too early. Sorry for the confusion this has caused.  

Webhooks will be available in Confluence 7.7.0 for Server and Data Center. Registering a webhook can be done through the UI or using the REST API. 

You can check it out right now in the Confluence 7.7 Beta, or take a look at the documentation:

• Managing webhooks (beta documentation)
• Webhooks   (developer documentation)