to add a new port to public zone

$ sudo firewall-cmd – zone=public – permanent – add-port=9090/tcp

firewall-cmd –permanent –zone=public –add-port=8080/tcp

to reload the configuration for the changes to take effect

$ sudo firewall-cmd – reload

firewall-cmd –complete-reload

to validate if the port is added

$ sudo firewall-cmd – list-all

To Test the port is listening

python3 -m http.server 8088