Retargeting / remarketing (Facebook and Google ads) using tracking events?

Is it possible to set up retargeting / remarketing for anonymous contacts (eg: abandoned cart) for Facebook and Google ads?

I have a Woocommerce shop, someone places items in the cart, but never purchases → I don’t have an email address, however I want to display Facebook and / or Google ads about the abandoned cart.My setup is:

  • Woocommerce GTM4WP plugin provides events
  • Events are sent to GTM
  • GTM routes events to Mautic
  • (I can potentially also send events directly to GA and FB here if needed)

What I figured out so far:
I set up Google Analytics and Facebook pixel in the config

  • I can identify anonymous contacts who put something into the cart → put them into a specific segment (using custom fields for customers that are updated through events from Wordpress)
  • I can create a campaign and send a tracking events to GA and FB in theory

Mautic tells me that the events are sent but I can’t see these “custom events” in either GA or FB

If the custom events would be sent, then I think I could set up targeting via custom event attributes, but I am not sure why is it not showing up. Is this doable somehow?