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.
Follow the tutorial in codabench wiki. 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.