# Open the terminal with Ctrl+Alt+T and install the openssh-server 
# package:
sudo apt update
sudo apt install openssh-server

# Once the installation is complete, the SSH service will start 
# automatically. You can verify that SSH is running by typing:
sudo systemctl status ssh

# Ubuntu ships with a firewall configuration tool called UFW. 
# If the firewall is enabled on your system, make sure to open 
# the SSH port:

sudo ufw allow ssh

sudo apt updatesudo apt install openssh-server

sudo ufw allow ssh

# Check this article