There are a couple of ways to enter a submission! You can submit directly from the hackathon's Devpost page (for example, http://pennapps-xiii.devpost.com), you can submit a new project from your portfolio, or you can submit an existing project from your portfolio.
Option 1: Submit directly from the hackathon page
Follow this step-by-step video:
Option 2: Submit a new project from your portfolio
Sign into your Devpost account and click either "Start a project" on the homepage or "Add a project to your portfolio" from your portfolio.
Give your project a name and click "Save and Continue." Fill out the submission form and click "Save."
You will see a pop up at this stage that asks if you are submitting to a hackathon or to your portfolio:
Click "Yes, I'm submitting to a hackathon!" and another pop up will appear with a list of all hackathons that currently have open submission periods:
Finish the last page of the submission form, and click "Submit to hackathon!"
Option 3: Submit an existing project from your portfolio
If you are submitting an existing project, find the thumbnail of the existing project, click the blue “Submit this project” button beneath it, fill out the submission form and remember not to skip any questions with a red asterisk . Then, click “Submit to Hackathon.”
Whether you submit a new or an existing project, you will see a green bar confirming this: