Auto-Fill e-mail in embedded form.

Hi All, 

I’m having an issue regarding the signup forms. 

I have created an embedded form on our new landing page to register for a specific list. Only exisiting Klaviyo Customers will get this e-mail and the opportunity to sign up. 

Now i’m looking for the option to automatically fill the e-mail address form Klaviyo into the form on the landing page. I know that there was a function a couple of years back but it seems to be gone by now. I tried another community solution with ?email= but it doesn’t work.

As an alternative, i could also see the option that the customer just needs to click a button on the landing page and Klaviyo will fill it by itself in the list (as all the data is already given).

Does anyone have a solution for this? 

Thanks!