So
First part of yout question for sure can’t be achieved, user can always see url of the site and copy paste that. Wix can not control this part, it’s controlled by browser.
But, solution for this case i believe is to create this page dynamically, after redirect from other page (probably passwrods page)
This can be done with custom router - Velo: About Routers | Help Center | Wix.com
But this will need some advanced developer skills from you, it’s one of the most sophisticated abilities of our platform