It depends what custom fields you’re trying to add and if they need to interact with other parts of the system, ie: do they need to show up on the help desk page ? do they need to show up in the Create Ticket page ?
The short answer is: it’s not easy to create custom fields if you want the user to be able to interact with them in the help desk. The help desk is fairly complex, and all custom fields plugins work in the admin only.
If you are looking for customization we can work with you to build what you want, however we do charge hourly for custom work. you can contact us directly here if you want more details about this.
https://support.smartcatdesign.net/
Best regards