BSP_EVENT_KEY_X event in ble_nus

Good day Nordic, 

I am starting to work over the ble_uart_central example, this is a project that uses bsp_event_handler to issue the events from buttons, but I cannot make it enter the BSP_EVENT_KEY_0 event or any simirlar. If i use the bsp example in the peripheral's  folder, everything works fine but for the ble_uart_central it does not work at all, the same with the ble_app_bps, key events are never generated . How can i activate them? should in configure separately the pins as well?