doctl is unable to find docker binary

Configuring Digital Ocean Container Registry

link : https://www.digitalocean.com/docs/kubernetes/how-to/set-up-registry/

After Successfully : Snap install doctl

#doctl regitry login
Error : unable to Find Docker binary . make sure docker is installed 

#docker --version 
Docker version 18.09.2, build 6247962

Github Issue : https://github.com/digitalocean/doctl/issues/709

Source: StackOverflow