This message was deleted.

Perhaps review support matrix: https://www.suse.com/suse-rancher/support-matrix/all-supported-versions/rancher-v2-6-7/ I do not see Kubernetes version 1.26 (or perhaps my Tea hasn't kicked in yet)

You need to use a version of K3s that is compatible with Rancher. for now that is a 1.25 release.