You can add a Facebook Pixel to your website quickly and easily. Once you have you created your Facebook Pixel code
In the left hand menu go to Settings > Configuration > Third Party > Meta
Paste your Facebook Pixel ID into the Pixel Code field. https://support.shareaholic.com/hc/en-us/articles/360000428223-How-do-I-find-my-Facebook-Pixel-ID-
Your changes will automatically be saved