Is there a way to enable Fancybox to change to the adjacent gallery by simply using the 'up' or 'down' arrow keys?

[jsV8]

Describe the bug

I am currently working on a layout that consists of a vertical column of thumbnail images, each linked to its own gallery with additional images. When the user clicks on a thumbnail image, Fancybox opens, allowing them to navigate through the images within that specific gallery using the arrow keys.

You can view a demo of this setup here: http://jsfiddle.net/Q6tmq/

My question is how can I customize the functionality so that when the 'up' and 'down' arrow keys are pressed, instead of moving to the next or previous image within the current gallery, it will display the first image from the next or previous gallery?

In essence, I want users to be able to open Fancybox, navigate through all the images in all galleries present on the page without having to close Fancybox each time.

https://javascripter.space/questions/is-there-a-way-to-enable-fancybox-to-change-to-the-adjacent-gallery-by-simply-using-the-up-or-down-arrow-keys

Reproduction

<!-- GALLERY 1 -->
<li>
    <!-- THUMB -->
    <a class="fancybox" rel="gallery1" href="http://fancyapps.com/fancybox/demo/1_b.jpg">
        <img src="http://fancyapps.com/fancybox/demo/1_s.jpg" alt=""/>
    </a>

    <!-- IN-GALLERY IMAGES -->
    <div class="hidden">
        <a class="fancybox" rel="gallery1" href="http://fancyapps.com/fancybox/demo/2_b.jpg"></a>
        <a class="fancybox" rel="gallery1" href="http://fancyapps.com/fancybox/demo/3_b.jpg"></a>
    </div>
</li>

<!-- GALLERY 2 -->
<li>
    <!-- THUMB -->
    <a class="fancybox" rel="gallery2" href="http://fancyapps.com/fancybox/demo/4_b.jpg">
        <img src="http://fancyapps.com/fancybox/demo/4_s.jpg" alt=""/>
    </a>

    <!-- IN-GALLERY IMAGES -->
    <div class="hidden">
        <a class="fancybox" rel="gallery2" href="http://fancyapps.com/fancybox/demo/5_b.jpg"></a>
    </div>
</li>

$(".fancybox")
.fancybox({
    helpers : {
        title : {
            type : 'over'
        },
        overlay : {
            css : {
                'background' : 'rgba(0, 0, 0, 0.7)'
            }
        }
    }
}); 

Additional context

No response

[fancyapps]

Hi,

Sorry, such functionality is not currently provided, as it is not clear how many users would need it. If enough people asked, it would be implemented.

I also wonder how users could know that pressing these keys would change the gallery, wouldn't they be surprised if they accidentally pressed them.