Hi,
Please check here to download latest OpenSDA firmware for FRDM-K66F board.
I tested to download Segger J-Link firmware from here and after updated the firmware, I could drag and drop application image (*.bin) to MSD USB disk (FRDM-K66FJ).

About how to update FRDM-K66F on board OpenSDA firmware, please check below picture:

Wish it helps.
Have a great day,
Mike
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