Once your project has been set up in Red Hat Partner Connect, the interaction with the certification service is done through GitHub. Specifically, through https://github.com/openshift-helm-charts/charts.
In that GitHub repository, there will be a directory named under partners/ for your company. Note that the name will the the same as the container registry namespace you set when certifying your containers.
Within your company's directory, there will be a subdirectory for each chart certification project you create in the previous step. To verify that it is set up correctly, review the OWNERS file. It should contain information about your project, including the GitHub users that are authorized to certify charts on behalf of your company.