Silverstripe comment module not working

Question

I installed the Silverstripe comment module, but the comment form on the page does not appear as they said in setup.md

Out of the box, the module adds comment support to all pages of your site. This function can be turned on and off for each page in the CMS on the tab Behaviourfor this page. Once the checkmark Allow Commentsis checked, republish and view the web page.

but the checkbox Allow Commentsalso does not appear here my composer .json: -

{
    "name": "silverstripe/installer",
    "description": "The SilverStripe Framework Installer",
    "require": {
        "php": ">=5.3.3",
        "silverstripe/cms": "3.2.1",
        "silverstripe/framework": "3.2.1",
        "silverstripe/reports": "3.2.1",
        "silverstripe/siteconfig": "3.2.1",
        "silverstripe-themes/simple": "3.1.*",
        "assertchris/hash-compat": "^1.0",
        "colymba/gridfield-bulk-editing-tools": "^2.1",
        "silverstripe/comments": "^2.0",
        "silverstripe/lumberjack": "^1.1",
        "silverstripe/tagfield": "^1.2",
        "silverstripe/blog": "^2.3"
    },
    "require-dev": {
        "phpunit/PHPUnit": "~3.7"
    },
    "config": {
        "process-timeout": 600
    },
    "prefer-stable": true,
    "minimum-stability": "dev"
}

What am I missing?

Answer 1

Just add

SiteTree:
  extensions:
    - CommentsExtension
  comments:
    require_login: true

in / mysite / config.yml

"/dev/build? flush = 1"