@NeeeeB Thank you for this! Though I am having some issues and I hope you can give me some guidance. I am using an external hard drive which houses all my games in a 'roms' folder. Whenever I try to select the folder I receive an error:

Oops!! It looks like you selected the wrong folder!
Please select the root folder where your systems folders are stored.

I've tried connecting to my Raspberry Pi, but it just tells me the same thing.
Thanks for your assistance.