How to generate Oracle Apex Barcode

Declare 

VTotal number;

begin

VTotal:=nvl(:P1_qty,0);

for i in 1..VTotal

loop

htp.p('<img style="height:60px;" src="https://barcode.tec-it.com/barcode.ashx?data='||:P11_BARCODE_NUMBER||'" alt="barcode"/>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;');

end loop;

htp.p(' </div>');

end;