The D8 policy was that this instance was supported for development purposes only. This is extended in D9 to include ops purposes but there is still no end user function here. It will participate in the SSO for operator level users.
CLiu's main drupal core is D7 which is publicly supported by drupal.org at least thru its d.o EOL in November 2022 and the version of it here after that. The specific support of Symfony versions is done on a per module group requirement basis.
However D9 does have an increased developer and operations significance and DRD 9 admin for Cliu(d7) sites is a part of the production SB Network codeset.
Login here is for admin/operator use.