The standard fields, including "Priority", cannot be customized or removed. But you can hide or disable the field on the "New ticket" page using custom CSS; here is how to do that.
1. On the Administration tab, click General settings and then click Advanced CSS & JS on the screen that appears.
2. Paste your code in the Custom CSS styles field.
3. Click Save to save the changes.
Here is the code to be used depending on your objective.
To completely hide the Priority field:
#PriorityID { visibility: hidden; }
To disable the Priority field:
#PriorityID { pointer-events: none; }
Note: Please remember that this is not a standard workaround, and you are making the changes in the code at your own risk.
Jitbit Helpdesk ticketing system is our flagship product. Its a great helpdesk software app offered both as a hosted and "on-premise" versions.