For R. Johnson jersey tonight, how early should I be there?

I saw comments on a Facebook post that people will be there around noon for the jersey. I am not sure they were trolling (because of laughing emojis) or I actually have to be there around noon to secure the jersey. I was thinking about 4pm (I have a 2:30PM tour at Lumen Field). How early do I need to be in the line to secure the jersey?