Lab 8.1, Error pulling image

Hello I am following the the lab exercices and I am getting error when I try to pull the ningx container from the registry

The error is : ImagePullBackOff

and when I do kubectl describe pod shell-demo here is the stacktrace :
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 5m28s default-scheduler Successfully assigned default/shell-demo to minikube
Normal Pulling 2m8s (x4 over 5m27s) kubelet Pulling image "nginx"
Warning Failed 93s (x4 over 4m52s) kubelet Failed to pull image "nginx": Error response from daemon: Get "https://registry-1.docker.io/v2/": net/http: request canceled while waiting for connection (Client.Timeout exceeded while awaiting headers)
Warning Failed 93s (x4 over 4m52s) kubelet Error: ErrImagePull
Warning Failed 71s (x6 over 4m51s) kubelet Error: ImagePullBackOff
Normal BackOff 17s (x10 over 4m51s) kubelet Back-off pulling image "nginx"

and when I am reaching https://registry-1.docker.io/v2/ I am getting these :
{"errors":[{"code":"UNAUTHORIZED","message":"authentication required","detail":null}]}

and it directly respond no timeout.

can you help figuring it out please.