www.makemkv.com

I have a collection of movies in .iso form. Because they are large files I keep them on an external hard drive. I know how to use Makemkv to turn them into .mkv files. My problem is locating them. How do I locate them using the file finder icon? The drives don’t show up like they do from my Linux file finder app.

Is there a reason why you don't extract the movie files from them, and name them with the name of the movie? That's generally the reason for using an app like MakeMKV...

You need to select Computer and then go to where the drives are mounted (probably /media or /mnt).

You wrote: “ You need to select Computer and then go to where the drives are mounted (probably /media or /mnt).”.
That’s what I’m trying, but the drives do not show up, unlike they do when I’m simply using a file finder. Maybe my version of Makemkv needs some tweaking whatever that might be.

Are you using a snap or flatpak? If so then you probably need to give it permission to access the drives.