Register on Codabench to this existing competition IRIS-tuto and make a submission (you can find the necessary files here): sample_result_submission and sample_code_submission. See this page for more information.
Create your own private competition (you can find the necessary files here ). See this page for more information.
Setting up a local instance of Codabench
Follow the tutorial in codabench Docs. According to your hosting OS, you might have to tune your environment file a bit. Try without enabling the SSL protocol (doing so, you don't need a domain name for the server). Try using the embedded Minio storage solution instead of a private cloud storage.