Sorry to delay in responding, yes as i mentioned above, i had to remove my redis from docker and reinstall a new image with this command

docker run --name=redis -p -d -t redis:alpine

and now when i test my ip and port on

Open Port Check Tool - Test Port Forwarding on Your Router

the status of my redis port is closed. I think which to configure firewall in droplet digital ocean is a good idea too, and i will configure soon.
Thanks for the help!