Hi Emily
I am afraid this is not how you are supposed to do it.
As outlined here https://drupal-community.web.cern.ch/t/create-a-test-site/1345, https://drupal-community.web.cern.ch/t/create-a-drupal-9-clone/1346, and at https://drupal-tools.web.cern.ch/create-a-clone-or-test-website, creation of test and clone websites is done through the Webservices Portal https://webservices-portal.web.cern.ch/.
Creating a website like you have done, through the old infrastructure, means that your website is on the old infrastructure and not on OpenShift. This also means that you are unable to use the Upgrade Status report as outlined at https://drupal-tools.web.cern.ch/how-to-prepare-your-website-its-drupal-9-upgrade to confirm your progress and changes. This is further the reason why you cannot see it on OpenShift. You are unable to add it yourself.
If you can confirm that your test-sce website has all the necessary changes to be compliant with Drupal 9 (though I am not sure how you can confirm this without the Upgrade Status report), we might be able to migrate first your test website to OpenShift and then clone to production, or possibly clone it directly on to your production site. This is by no means standard procedure, however.
Thanks!