I am making a survey platform to host various google form link from user, I hope to detect when a user have submitted the survey. When I have done is I inframe the survey link and try to add an eventListener to the submit button with class e19J0b CeoRYc. However this failed as it is a cross-domain access.

function add_listen(){
            var button = document.getElementById("popup_preview").contentWindow.document.querySelector('.e19J0b.CeoRYc');
            button.addEventListener("click",SUBMIT);
        }

I have a function like this. Is there other way that I implement this feature? Thank you!