Are the 5 blanks supposed to be populated by the key.81 or is that just a general tip about the puzzle?

I'm not sure what form the answer should be in. I've tried many 6-letter combinations of the input letters and the output letters on the sides (and the other sides that the outputs aren't going to) but no idea if this is even the format the answer is looking for. Will the answer be obvious when I see it? Is it a real word? Very confused.