kernel-rt from Kernel:SLE15-SP3-RT-LTSS project
Select Your Operating System
Add repository and install manually
For pool run the following as root:
zypper addrepo https://download.opensuse.org/repositories/Kernel:SLE15-SP3-RT-LTSS/pool/Kernel:SLE15-SP3-RT-LTSS.repo zypper refresh zypper install kernel-rt