Zebra Technologies ZTC GC420t send ZPL blank printing

We are not able to print Barcode label to GC420T

OS - Ubuntu 18.04 LTS(Linux)

ZPL we are sending


^FO300,45^A0N,20,20^FDChuridar piece^FS

We have tried below options


lpr -P CupsPrinterName -o raw path/to/label.zpl

2) Direct printing

cat label.zpl > /dev/usb/lp0

None of the options worked. Our application is Java and we have initially tried from Java and didnt worked out.

Please guide usĀ  some hint to debug. Our expertise is on Java and Linux