Hi Tero,
You’ll need a tool like Hyros that will collect those events from Hubspot and then sent them to Facebook. Then you’ll be able to optimize your ads for those specific Hubspot events. See HYROS Documentation - Setup Guides & API Reference
Here’s an example of a FB ad expert doing the thing you are asking about: https://www.facebook.com/permalink.php?story_fbid=pfbid02ewrZmW4jdiVus4aJzBfzgdwxHhnNHxPqfyVNH3E3iCu7MQKhFzh5wPEjDGGQtCQ3l&id=5138089