Hey all! I just integrated mine into my site; elements have changed to make sure it works:
-The site needs to be https.
-Yo no longer need the AppID, so you just copy-paste the code from the Facebook page settings and the Integrator steps.
-If you want it to work from YOURSITE.webflow.io, remember to add this domain in the list that Facebook asks you to add. Or else you won’t be able to previw from Webflow.
As per implementing in the site in Webfow Desiger, an Embed Code at the top of the hierarchy below de Body, will be sufficient for it to work.
Happy New Years!