How to enable PeopleCode Auto-Complete feature in App Designer for PeopleTools 8.54

Yes! you heard it correctly!. PeopleTools 8.54 comes with long waiting feature in App Designer, Auto Complete. Lot of IDEs in today's market provide code auto completion feature for any programming language of your choice such as java, C#, php. However, PeopleSoft App Designer lacks this feature until PeopleTools 8.54.
According to PeopleBooks, it says

"The PeopleCode Editor provides an auto-complete feature for PeopleCode application classes, built-in classes, built-in functions, system variables and constants. The auto-complete feature displays the possible options when you insert a period (.) or dot after an object.

The auto-complete feature also supports the display of a tool tip when you hover the mouse over the selected list item. The tool tip displays the method name, parameter type, and the return type.

The auto-complete feature is not applicable for objects that are declared as automatic variable and objects that get resolved at run-time."