Window handle machanism is broken - need replacement part please

HI Swisco team - we have a white window crank mechanism that measures 4" length and is broken inside, so that when I turn to close/ lock the window, it has a click/ broken sound inside and is unable to lock properly. I think I need to replace the 4" part and the extension arm (not sure if this is sold as one set ?) Can you please provide me the parts required to replace the broken mechanism inside the white 4" piece. Pics are attached in this request. Thanks, Adrian