Set player name to variable from using a command

Hello all,
I am working on a Priority Cooldown script and was wondering on how to get a certain variable. So my idea is… User types /p and it starts a priority and on screen it writes "Priority in progress by {Username} down by the mini map. I have the on screen display already but the only thing I don’t have is the player name. I would like for it to capture the steam name that the player has set. Thank you!

GetPlayerName(source) will give you the player name.