I found K240 keyboard and M212 mouse without the usb, both are in black with blue highlight color, and I did not want to trow it away.
I later found (claude told me) that it use the same usb with the M221 silent pink mouse. that USB usually pair to 2 devices
So down load the Logitech Connection Utility Software, and pair the keyboard to the current M221 mouse.
Compare M212 blue mouse, which is not height as the M221 pink mouse , I prefer the pink one shape, though color mismatch.