Your full code base should be uploaded to portals like GitHub and the link should be shared. The solutions should be open sourced.
There should be a working link/file of the solution you have made. If it's an app then you could either publish and get a link or upload to google drive and share the link. In case you've chosen an idea from the scripting section, you can resubmit the link to the code here.
Everyone is expected to make a video explaining the core logic of the code they made. They could use the read me files in their GitHub / the code itself / or screen sharing their solution made.