During a refinement stage, applicants are expected to revise their entry and/or complete one or more extra tasks.
If your applications have made it to a refined phase, first of all, congrats! You'll be able to access your applications by following these steps:
Login to your account by clicking on the profile icon.
2. Once logged in, you'll be able to see your profile picture and the Edit and View options for your application.
3. Click on Edit to open your application on a new tab. There you see your pending tasks.
After all tasks are completed, click on submit.
P.S. the screen above is illustrative, as the refinement tasks will vary from challenge to challenge.
If you still in doubt, don't forget to check out the challenge community, as you may find answers to your questions there. If you don't, leave a message to the challenge team on the support channel.