@Felipe24 - Are those signups or trials forms? The current options for HubSpot ad events are lifecycle stages or forms.
If not, have you considered just setting up lifecycle stages for this use case? If you aren’t using them for other reporting, you could customize them for these HubSpot events and ignore them otherwise.
You can set up workflows to set the lifecycle stage based on the property values and you can customize the lifecycle stages to meet your needs.