Wav files on my SD card

[SylvanStudios]

Greetings all...first time poster here
Managed to format my SD card and it appears on my Mac Mini M1 ...Can I simply drag and drop WAV files onto the card itself or do I need to create a folder first...or something else...?
The manual is not very detailed in this regard
When I go to load from the WAV files on the KP3+, that directory is empty...ie it looks like this [---]...Obviously not doing something right
Please advise
Roman