How to Add or Remove the firewall PORT rules in Ubuntu Linux

 To allow the port by the following command

$ sudo ufw allow 80/tcp

$ sudo ufw allow 443/tcp

You can also delete the port by the following command

$ sudo ufw delete allow 80/tcp

$ sudo ufw delete allow 443/tcp

Other way 

$ sudo ufw status numbered

$ sudo ufw delete {rule-number-here}

$ sudo ufw delete 2