Execute Object method from a custom button

On this really and using the config layer only, you can absolutely kinda already do that, you just need to configure the projection with a new projection action that calls the method in question. After that you can make the command which calls the projection action which does the server call to the PLSQL Package Method

The only caveat to what Simon’s said is that the PLSQL methods that are available for selection are those that do only have simple parameters (IN parameters of type VARCHAR2, NUMBER, DATE) or has no parameters at all.