Open the candidate's repository. Click on the candidate and head over to the Coding test tab. From there, you will find a link to the candidate's code repository that lies in GitHub.

Once you have the repository opened, you should see a button labeled Branches. Click on that.

Here, you will see all available branches in the project. A branch is another way of saying a version of a project. When a candidate starts working on their coding test they create their own branch which is used to store any code they write.
​
If you now look underneath the heading Active branches, you should find the branch that your candidate has been working on. It is often titled implementation, patch or similar. Click on that branch.

Now, you are looking at the candidates submission. You'll likely see other folders than before, and more files that have been added. Click on the green <> Code button, and under the tab Local you can download all the files as a zipped folder.