List existing firewall rules
To delete firewall rules from UFW, we first need to get a numbered list of the rules that are currently configured. Open a terminal and enter the following command to list all the rules:
$ sudo ufw status numbered
Remove a firewall rule
Take note of the number that corresponds to the firewall rule you’d like to delete. In our example, we’re going to delete rule #2, which allows connections over HTTPS (port 443) on IPv4. The following command deletes rule #2:
$ sudo ufw delete 2
After running that command, you’ll be asked to confirm that you want to delete the rule. Just enter y and press enter to continue. Now that it’s been deleted, you can check UFW’s list of rules once again to make sure that the rule no longer appears:
$ sudo ufw status numbered