Starting October/November 2024, RedHat switched to Simple Content Access and entitlement certificates will no longer be available in the RHN UI. To get a certificate, you will need to install a tool like subscription-manager on your RedHat server, and get the certificate from “/etc/pki/entitlement”. To register using subscription-manager and generate the certificate, the below command can be used.
susbscription-manager register
This will prompt for the username and password that are used in the RedHad subscription. Once the credentials are entered correctly, under “/etc/pki/entitlement”, two .pem files will be created, <id>-key.pem and <id>.pem.