I have a website implemented by Laravel 5

I don't have any problems with telegram link preview itself.

Some of my pages are behind authentication which means users need to login to access those pages.

The problem is, when I put one of those links(that required login) on telegram, it shows the preview for the login page instead of the intended URL. It is completely understandable and expected but I don't know how to solve it.

My first guess was that telegram uses a bot to do this but apparently it does not.
I also tried working with user agent but I realized that the user agent it uses for this job is the same as browsers. 

Any other ideas?