Hi other time Nikola! In this topic you say that we can put in our URL the name o, for example utm_value, and if we have a input with the same name in slug, this field will autofill. I can try this function and works ok if i put this in a single page. If I put the shortcode in a Popup, don't fill it (I use popup maker plugin).

Do yoo know how can I pass the vars to the popup?