IF you want to print several labels in the same run, you need a loop with the utl_tcp.WRITE_TEXT inside the loop, but the open and close connection statements can be outside the loop
Apex versions 5-19 requires an Oracle Database release 11.2.0.4 or later. So, only version 4 supported for 11.2.0.2. You should consider upgrading to version 11.2.0.4...