(1) Your labels are loaded in upside down
Please ensure your labels are properly loaded. The print side should be facing up. See the image below:
(2) Ensure your labels are "Direct Thermal" labels.
(3) Turn the printer off. Then Press the Feed Button (the top circular button) and hold it until you turn on the printer, release. Printer will print a test page. If test print looks good, please try to print your label again.