For standard run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tdz:branches:Kernel:stable/standard/home:tdz:branches:Kernel:stable.repo
zypper refresh
zypper install kernel-default
For LEGACYX86 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tdz:branches:Kernel:stable/LEGACYX86/home:tdz:branches:Kernel:stable.repo
zypper refresh
zypper install kernel-default
For ARM run the following as root:
zypper addrepo https://download.opensuse.org/repositories/home:tdz:branches:Kernel:stable/ARM/home:tdz:branches:Kernel:stable.repo
zypper refresh
zypper install kernel-default