Hi @Stefano468 welcome to the community. Based on this thread from another member with a similar question:
It sounds like you may need to get a developer for Klaviyo partner to build your own custom event. You could use a workaround with a Klaviyo form. But I haven’t done this before, so maybe there’s another member here who could add more details.
However, if it’s a regular eCommerce store, I would also add a disclaimer that submitting the contact form would also add them to your email list. If it’s not clear, you may see higher than normal unsubscribes (or even spam marks). I know every brand I reach out to as a customer that I don’t necessarily want to be added to their newsletter list.
Hope that helps a bit.