Any modern machine with 2ghz multi core CPU, 8GB of RAM and any graphics card that supports DX11, Vulcan or OpenGL 3.0.
Unless you have a PC that's over 10 years old you're good and even then you probably could make Duckstation run on it.
You only need a beefy PC if you try to set the enhancements to absurd levels like playing at 4k with the XBR filter on.
Only real requirement is that you use windows 10 or newer and for Linux Ubuntu 20.04 or newer.