Add phases to your Gantt view schedule and assign schedule items to phases

To show or hide phases on your schedule, navigate to the relevant Job > Project Management > Schedule. On the right-hand side filter, as shown below, you can toggle phases to show on your Gannt schedule view.

You can also bring up further options by double-clicking on a schedule item. Within the Add/Edit Schedule Item side menu, you can select which phase you want the item to belong to. This is shown in the image below.