How to scroll within a frame in FancyBox?

Question

fancyBox

Good day to all!
The essence of the question is this:
I am making a website for a web studio and decided to implement a portfolio using FancyBox.
It turned out that when you click on a small screen on the site, the full screen in high quality is actually displayed in the FancyBox frame, but the picture is adjusted to fit the screen and it is impossible to see anything on it.
After that, I put Supersized effect - the picture is really stretched, but now it is cropped.
Tell me how to implement scrolling inside this frame.
I will be grateful for any answer.