You can link directly to your Facebook page using a facebook button by following the instructions below:
You will now need to place the code into a HTML fragment and place it on your page. To do this, please read out guide.
You will be returned to the "HTML Fragments" screen, where your new fragment will now be listed. You will then need to add the HTML Fragment to your page using a Custom Block.
A grey graphic will appear in the place that the HTML fragment should appear on your published site. This is called a "placeholder", and will take the place of your HTML item when you are designing and editing your site. It will be viewable when you publish or preview your site after saving.