Here is the code I'm trying to run. The error message in the listDir function keeps popping.

Anybody got examples or any cue?

thanks

#include <Arduino.h>
#include "FS.h"
#include "M5Stack.h"

void setup(){
    M5.begin(true, true, true, true);
    M5.Power.begin();
    Serial.begin(115200);

    listDir(SD, "/", 0);
    delay(5000);

}


void loop()
{
  
}
void listDir(fs::FS &fs, const char * dirname, uint8_t levels){

    M5.Lcd.printf("Listing directory: %s\n", dirname);

    File root = fs.open(dirname);
    if(!root){
        M5.Lcd.println("Failed to open directory");
        return;
    }
}