Open facebook sharing link in the facebook app.

Ok So I have a link like this:

Application.OpenURL(fbURL +
    "?app_id=" + appId
    + "&href=" + WWW.EscapeURL(link)
    + "&name=" + WWW.EscapeURL(name)
    + "&caption=" + WWW.EscapeURL(caption)
    + "&description=" + WWW.EscapeURL(description)
    + "&picture=" + WWW.EscapeURL(picture)
    + "&redirect_uri=" + WWW.EscapeURL(redirect));

which allows users to share something on facebook based on those parameters(name,link,caption,etc which are all strings). fbURL is just “Error”, and appId is the Facebook id of my app.
Now I want to open this type of link in the Facebook app for android if it is installed on the device, else I want to open this in a browser. I already know how to open it in the default browser but I can’t open it in the native facebook app. I’ve already tryied

Application.OpenURL("fb://"+fbURL +
        "?app_id=" + appId
        + "&href=" + WWW.EscapeURL(link)
        + "&name=" + WWW.EscapeURL(name)
        + "&caption=" + WWW.EscapeURL(caption)
        + "&description=" + WWW.EscapeURL(description)
        + "&picture=" + WWW.EscapeURL(picture)
        + "&redirect_uri=" + WWW.EscapeURL(redirect));

Can you help me please? Thanks.

Download and use Use FB Unity SDK from here
and

                FB.ShareLink(
                new Uri("https://developers.facebook.com/"),
                "Link Share",
                "Look I'm sharing a link",
                new Uri("http://i.imgur.com/j4M7vCO.jpg"),
                callback: this.HandleResult);

will share in FB app.