It’s not entirely clear what you’re asking, or what or if you’re using a pre-built integration between Hulk forms and Klaviyo. For now, I’ll assume you are, and so I will assume that it has a built-in event that gets sent to Klaviyo with every form submission. And if that’s true, you can create a flow with that event as the trigger. 

If all those assumptions are wrong, you’d have to create the event in Klaviyo with a custom integration, probably going into a platform like Zapier or Make first. So, the form would be submitted, you’d send the data into Zapier or Make, and then create a custom event in there to send the information into Klaviyo.

In either of those situations, I’m completely lost by what you mean by “but with Hulk form ID.” Do you mean that you only want one specific Hulk form to trigger the Flow? And if that’s true, then:

• Scenario 1 with a pre-built integration, you can add a flow filter or trigger filter and specify the Hulk ID or Form Name, assuming the Hulk ID or Form Name gets passed into Klaviyo.
• Scenario 2 with semi-custom integration: Configure the Zap to only trigger on that form to begin with, or if that’s not possible, set the Zap to trigger on all form submissions, then add a filter step so that only the form you’re interested in moves through the rest of the Zap and sends the event to Klaviyo.

Thank you David!
Your assumptions are correct and I’m aiming for Scenario 1. However, what is unknown to me is, whether the the Hulk ID or Form Name gets passed into Klaviyo - that is the biggest question to which I didn’t managed to find an answer anywhere so far.