Actually it says "no commercial use". So you contact the designer, hopefully agree on a price, pay him, then use the font to enter the competition. Also, you should mention the font when you submit to the contest, and if you win.
I have used this in several university presentations and have recommended it to many peers and communication designers.
I think I found a bug with the font: https://rudloff.github.io/quicksand-bug/
(Very nice font though!)
Great thanks !