When you access the game for the first time you must create an account. You will have the option to do so with Facebook. We invite you to visit the article: "How to create an account?"
On the other hand, if you already have an account and wish to link it with the social network, you must access the Settings menu, and then click on the "Connect" option represented by a blue box with the Facebook logo.
You can also link your account from the "Games" section, selecting the list icon at the bottom of your home screen. When accessing, you will see the option "Connect with friends" in the upper left corner, and you must click on the "Go" button to confirm the link.
If you already have your account linked to Facebook and wish to unlink it, you must access the Settings menu and click on the option represented by the social network logo. By doing so, you will be redirected to a new window from which you must select the “Unlink” option.