https://www.epo.org/en/service-support/faq/can-i-publish-code-after-codefest
Can I publish the code after the CodeFest?
We state in the “Rules of Competition”, in the section “Intellectual property”, that participants own the rights to the Submission they create and, therefore, the rights to publish and upload the software. However, as also stated in the same section, if you use data and/or APIs or other copyrightable material owned by third parties, you must abide by the terms and restrictions they might have specified.
If you do publish your Submission, we would appreciate it if you acknowledge that the code and any results were created while participating in the EPO’s CodeFest on Green Plastics.