Thanks, that might be a way. But I think it works more directly.
Joey Keller has a documentation about a pixel trigger via image.
Via a
$curl = curl_init();
Function the URL is taken apart and the Mautic contact is created or updated.
When I’m calling my URL: website.xy?myID=123 a contact is created in Mautic with the value: 123. And any time I call it again, another contact is created.
So my question is: How do I get the value of 123, arriving at Mautic via filling the form and placing 123 in the ID field together with the other values submitted by the form?