Sky Replacement File Storage

I have several thousand skies that I use sometimes with Sky Replacement option in photoshop. I know how to upload images in the Sky Replacemnt panel but where exactly are they stored. I have searched the file name and it shows up in my folder (on an external hard drive) but nowhere else and yet if I try an upload say 1000 of these files I very quickly run out of HD space.

it was suggested to look in Library > App Support > Adobe > Adobe Photoshop 2026 but within that I cannot see any files being stored. 

I am suing Mac OS Sequoia 15.6 and Photoshop 2026.

Thanks.