I have installed open-iscsi, the services are actually running, but the kernel module is missing:
/home/sles # modprobe iscsi_tcp
modprobe: FATAL: Module iscsi_tcp not found in directory /lib/modules/5.14.21-150400.24.41-default
I am using SLES15SP4 VM (vmdk) - updated to latest version inside vmware hypervisor.