I use some 3rd party api that updates my redux store with next code

createStore.dispatch(
      initSdk({
        config: getConfig(),
        onReady: onReadyCallback,
      }) as unknown as Action
    );

where onReadyCallback updates redux with my custom ready flag:

 const onReadyCallback = () => {
      createStore.dispatch(updateServiceStatus(true));
    };

How to test this callback if I have to run initSdk and cannot mock it like:

jest.mock('@someAPI/functions')

In other words how to mock onReadyCallback?