CORS Policy

This does not work for me, I woul like to access elements of my wix website through iframe of a non-wix website but I can’t make it work. Anyone that has another solution?
Extra info: the page I want to manipulate is a password-protected page of which I know the password, I would want it to automatically change the input value to the correct password and submit so that only people that access my non-wix website can access the wix website through that iframe.