To access updates for SLE, you need an account with SUSE Customer Center and a SLE Product Key.
SUSE Customer Center is a web portal that allows you to manage your subscriptions, products, and
services from SUSE. A SLE Product Key is a unique code that activates your subscription and entitles
you to receive updates and support for your SLE product. You can register your product key with your
SUSE
Customer
Center
account
and
assign
it
to
your
system.
Reference:
https://documentation.suse.com/sles/15-SP3/html/SLES-all/cha-registration.html