What is the "openid" url of facebook?

[admin]

I made my

openid

in my site like this:

<pre class="lang-js prettyprint-override">

    livejournal: {
        name: 'LiveJournal',
        label: 'Enter your Livejournal username.',
        url: 'http://{username}.livejournal.com/'
    },
    wordpress: {
        name: 'Wordpress',
        label: 'Enter your Wordpress.com username.',
        url: 'http://{username}.wordpress.com/'
    },
    blogger: {
        name: 'Blogger',
        label: 'Your Blogger account',
        url: 'http://{username}.blogspot.com/'
    },

And I want to add facebook as my openid provider, so, what is the url of facebook

openid

?

<hr>

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