SE24 is the ABAP CLASS editor if I am not mistaken.
in this tool you can create ABAP classes that can implement the interface as defined in a BAdI definition.
By mere creation of such ABAP class you have not (yet) created a 'BAdI' implementation - only a class that implements a certain interface.
In order to create a BAdI implementation you need to create one in corresponding tool - and use/reference the ABAP class implementing corresponding interface in it.
