Key in again (6)
I believe the answer is:
retype
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">key in again</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for retype that I've seen before include "Set (the same text) again on a word processor" , "Produce document again" , "Repeat work in pool" , "impress again" , "Put into printed characters again" .)