I'm currently setting up Remarketing with RTP data for Google Analytics and Facebook.
For the Facebook setup, the Marketo documentation states that:
"You need to have Facebook Custom Audience Pixel installed your website for this feature to work."
When visiting that page, this feature is noted as being "deprecated".
My guess is that I still need to add this pixel.
If it were my own website I would just try and see, but since I need to give these instructions to a client
I'd like to get this confirmed.