Modal Page - Catching URL

When you have a booking portal and you want to know what your users signed up for it’s currently not possible to do that via a modal, which would be a great usr-experience…The issue is that I’m not able to get the URL of the projekt-details block, which is crucial to understand where users signed up for. I only geht the modal URL… Being able to use a Modal (for a form for examle) AND get the list details URL would be a game changer