The error:
The connection to the server IP:6443 was refused – did you specify the right host or port?
sudo cp /etc/kubernetes/admin.conf $HOME/
sudo chown $(id -u):$(id -g) $HOME/admin.conf
export KUBECONFIG=$HOME/admin.conf
Also make this permanent:
echo 'export KUBECONFIG=$HOME/admin.conf' >> $HOME/.bashrc
source ~/.bashrc