You can enable the Facebook "Like" feature from the Options > Social section in the settings of your event. Follow along below for details on adding this feature.

Add FB like button:

This option allows you to add a Facebook like button that your guests will have the choice of clicking when they send their media. To enable this feature, click the box for Add FB like button. Then where it says URL to "like" enter your clients Facebook page URL. Then for "like" message enter a message that the user will see. When a guest tries to share, they will be given the option to like the page. 

NOTE: The guest will be required to sign in to their Facebook account in order to complete the process.

Congrats! You're now all set to Like and Check-in during your event!