You need to post your best Sol image rendered in Unreal Engine with the hashtag #SolRemix to either Twitter, Facebook, or Instagram and mention @NVIDIACreators. Please note that you must enter by 09/30/2019 at 6:00 PM PST. Their judges will review submissions and announce winners on 10/15/2019. One other thing: you don’t have to do it with RTX on, but it would be a plus.
You can get more details here.