Yes, you can add your Facebook Pixel tracking code to your ConvertKit Landing Pages!
NOTE: Our current Facebook Pixel implementation will track pageviews only. Conversions tracking requires separate code that would need to be configured on your own website (or thank you page) at this time, following Facebook's instructions.
From the Landing Page editor, look for the </> icon on the right toolbar:
From there you have the option to add several types of tracking codes to your Landing Page. For the Pixel, look for “Facebook Business”:
Click “Facebook Business”, enter your Facebook Pixel ID, save your changes, and that’s all there is to it!