add licence key

I try to add licence key on your plugin. To do this, I try to add the code data-key=”$………” (with the good licence) in this file flowplayer6-video-player.php on line 179 <div id=”$player” data-ratio=”$ratio” data-share=”false” class=”{$classes}” data-key=”$………”>
but it doesn’t work, I can see on page the data-key=”$…….”.

If you have a solution thank you very much.