Need Help Switching Disks With Beetle PSX HW

The Beetle PSX HW core is amazing and I love using it. But being seeing as how I am fairly new to retroarch in general I just need some simple instructions on how to switch discs when playing multi-disc psx games. Any help with this would be greatly appreciated.

Just read the instructions here.

Thanks for the help my man I’ll give it a try and report back later to let you know if it worked or not.