GD works correctly and your script generates a warning while generating an image:
Warning: imagettftext(): Could not find/open font in /usr/home/abubakar/domains/rapidways.abubakar.serv00.net/public_html/admin/ticket_soft_copy_generate.php on line 57
You can see it by using e.g. curl
:
curl --output - -k "https://rapidways.abubakar.serv00.net/admin/ticket_soft_copy_generate.php?ticketno=1762140736285" | less
After removing additional warnings by binary editor you can see that the image is valid.
Check and fix your script.