Specify k3s version in rancher local cluster

In the release page there is information about supported Kubernetes versions and the default is v1.24.4. I use this command to run single node docker setup:

docker run -d --restart=unless-stopped
-p 80:80 -p 443:443
–privileged
rancher/rancher:v2.6.9

I need local cluster to be at Kubernetes version v1.21.14 but I don’t know how to specify this parameter? Is it even possible?

When installing Rancher on a single node with Docker you don’t specify the Kubernetes version. Why do you need the local cluster to be Kubernetes v1.21.14?