If you need a specific field added to your project that is not included as a default field in pjst_project12, you can create a custom field to meet your needs.
In this demo, I create a custom field to track the progress of tasks in my project. I associate the field with a list, and map each list item to a graphical indicator. Finally, I add the custom field as a column on the Gantt Chart view (Gantt Chart view: A predefined view that displays project tasks on the left side of the view, and graphical bars corresponding to the task's durations on the right side of the view.).