XBEE Receive Ok, Send problem

[DEAFBOY]

I use:
Arduino Leonardo
Arduino Wireless SD Shield
XBEE USB Adapter
Two XBEE S1

Receive from Button State was OK, but no sending (LED turn on/off). What's wrong with code?

#include <SoftwareSerial.h>

const int buttonPin = 2;
const int ledPin = 13;

int buttonState = 0;

SoftwareSerial xbee (0,1);

void setup() {
  xbee.begin(9600);
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin, INPUT);
}

void loop(){
       
  if (xbee.available() >0 )
  {
    char ch = xbee.read();
    if (ch == '1')
    {
      digitalWrite(ledPin, HIGH);
    }
    else if (ch == '0')
    {
      digitalWrite(ledPin, LOW);
    }
  }
  buttonState = digitalRead(buttonPin);
  
  if (buttonState == HIGH) {
    xbee.println("Button pressed!");
    delay(500);
  }
}