I suppose that you are using wrong secret for Bearer Token. Generally, you have to create ServiceAccount and then assign it appropriate service role via ClusterRoleBinding entitle log in to Dashboard using Bearer Token. Find more information about Kubernetes Dashboard Bearer Token authorization here.

for enter in dashboard in a vcluster with virtual machines need a handler netwroks for external ip containers i have a post from this https://piensoluegoinstalo.com/kubernetes-cluster-dashboard-on-premise/

the answers is use metallb

https://piensoluegoinstalo.com/kubernetes-cluster-dashboard-on-premise/

vi metallb.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  namespace: metallb-system
  name: config
data:
  config: |
    address-pools:
    - name: default
      protocol: layer2
      addresses:
      - 192.168.1.240-192.168.1.250

kubectl create -f metallb.yaml

Create certificate for you ip external of a container dashboard and add this resolver in hosts file resolve ip, i used "dashboard" for name domain

mkdir $HOME/certs
cd $HOME/certs
openssl genrsa -out dashboard.key 2048
openssl rsa -in dashboard.key -out dashboard.key
openssl req -sha256 -new -key dashboard.key -out dashboard.csr -subj '/CN=dashboard'
openssl x509 -req -sha256 -days 365 -in dashboard.csr -signkey dashboard.key -out dashboard.crt

kubectl -n kube-system create secret generic kubernetes-dashboard-certs --from-file=$HOME/certs

kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/master/aio/deploy/recommended/kubernetes-dashboard.yaml

kubectl -n kube-system edit service kubernetes-dashboard

CHANGE TYPE TO LOAD BALANCER

apiVersion: v1
kind: Service
metadata:
  annotations:
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"k8s-app":"kubernetes-dashboard"},"name":"kubernetes-dashboard","namespace":"kube-system"},"spec":{"ports":[{"port":443,"targetPort":8443}],"selector":{"k8s-app":"kubernetes-dashboard"}}}
  creationTimestamp: "2019-04-24T22:21:15Z"
  labels:
    k8s-app: kubernetes-dashboard
  name: kubernetes-dashboard
  namespace: kube-system
  resourceVersion: "1753"
  selfLink: /api/v1/namespaces/kube-system/services/kubernetes-dashboard
  uid: 4612785f-66df-11e9-8180-000c29e7b067
spec:
  clusterIP: 10.110.50.44
  externalTrafficPolicy: Cluster
  ports:
  - nodePort: 31394
    port: 443
    protocol: TCP
    targetPort: 8443
  selector:
    k8s-app: kubernetes-dashboard
  sessionAffinity: None
  type: LoadBalancer
status:
{}

kubectl -n kube-system get service kubernetes-dashboard

nano admin-user.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kube-system

kubectl create -f admin-user.yaml

nano cluster-role.yaml

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kube-system

kubectl create -f cluster-role.yaml

kubectl -n kube-system describe secret $(kubectl -n kube-system get secret | grep admin-user | awk '{print $1}')

https://youtu.be/nZ-CDc7PjSg

I have this issue when I try to get access to the dashboard via kubectl proxy using plain http and public ip.

Error details: kubectl proxy produces errors http: proxy error: context canceled in console, in browser after you click "sign in" one of the requests which ends with /plugin/config returns json with MSG_LOGIN_UNAUTHORIZED_ERROR but the browser doesn't display any error.

The solution (source)

kubectl port-forward -n kubernetes-dashboard service/kubernetes-dashboard 8443:443 --address 0.0.0.0

Of course you can use your interface ip instead of 0.0.0.0 if you want to bind it to one interface only. Then go to https://your.external.ip:8443/, it'll redirect you to https://your.external.ip:8443/#/login and you'll be asked for the token. Next, as described here:

kubectl -n kube-system describe secret $(kubectl -n kube-system get secret \
| awk '/^deployment-controller-token-/{print $1}') | awk '$1=="token:"{print $2}'

https://github.com/kubernetes/dashboard/wiki/Accessing-Dashboard---1.7.X-and-above

I have a note:

The Dashboard should not be exposed publicly using kubectl proxy command as it only allows HTTP connection. For domains other than localhost and 127.0.0.1 it will not be possible to sign in. Nothing will happen after clicking Sign in button on login page.

looks like the token is Base64 encoded. Did you tried to decode it before pasting it into the token field? see: https://kubernetes.io/docs/concepts/configuration/secret/#decoding-a-secret