One of the DC requirements is to submit a paper to PETRA 2020. The paper can be either a Full, Short, Poster or Workshop paper. You can find more details on the deadlines and the length of the different papers at http://www.petrae.org/deadlines.html
You won't be able to submit the DC application unless you select 'Yes' and provide a paper abstract.
NSF Travel Award (Pending Final Approval) is only available for accepted DC students studying full-time in the USA. If you are a local student or an international student studying in the USA, then you are eligible to receive the NSF funds.