Calls to action help drive people from Facebook to take actions that are important to your business (ex: booking appointments at your salon). You can add a call- to-action button to your Page at no cost.
To add a call-to-action button on your Page that directs people to your website:
- Go to just below your Page’s cover photo and click + Add a Button.
- Choose your call-to-action, and enter the URL for your website.
- Click Create.
Once you’ve created a call-to-action button, you can track the number of people who have clicked on the button.
More info from Facebook.