Serial1 is not reading the Xbee on a Arduino Due

I am trying to test simple communication between a Xbee on my Arduino Due and a Xbee linked to XTCU. I attached jumper wires from RX and TX to RX1 and TX1 (Serial 1 hardware port) but I cannot send or receive data between the Xbees. I tested the Xbees previously with an Arduino Zero talking to the XTCU and it worked flawlessly.

This is my code:

char c,d;

void setup() 
{
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial1.begin(9600);

}

void loop() 
{
  // put your main code here, to run repeatedly:
  if (Serial1.available())
  {
    c = Serial1.read();
    Serial.print(c);
  }
  else if (Serial.available())
  {
    d = Serial.read();
    Serial1.print(d);
  }

}

My wiring is attached. What am I doing wrong?