You can set the type of output API functions (all API functions or only initialization API functions) by selecting [Output all API functions according to the setting/Output only initialization API function] from [Code Generator Setting] tab >> [Generate File Mode] >> [API output control] in the Property panel.

In the Code Generator, select [Project name (Project)] >> [Code Generator (Design Tool)] >> [Code Preview] >> Peripheral function node >> Source code node >> API function node in the Project Tree panel. Setting That Determines Whether or Not to Generate Source Code can be set in units of API functions by selecting Generate Code/Not Generate Code from the context menu, which is displayed by right clicking the mouse.