You have received a requirement to add the "Gantt" button to the Project page layout.

How to Add the "Gantt" Button

Step 1:Navigate toSetupin Salesforce.

Step 2:Go toObject Managerand selectProject.

Step 3:OpenPage Layoutsand select the active page layout.

Step 4:Find the"Mobile & Lightning Actions"menu.

Step 5:Drag and drop the"Gantt"button onto the layout.

Step 6:Save and verify the changes in the Project record.

Why Not Other Options?

Option A:Custom Settings (Page Preferences)does not control button visibility.

Option B:Lightning Record Pages requireDynamic Forms, which arenot in usein this scenario.

FF-PSA v15 Customer Overview.pdf, Page 6​.

References: