1. Disable the Firewall: To disable firewalld service please run the following command.

sudo systemctl disable firewalld

2. Enable the Firewall: If you want to enable the service please run the command.

systemctl enable firewalld

3. Stop the Firewall: You can also deactivate the service using the following command

systemctl stop firewalld  

4. Start the Firewall: To activate the command run 

systemctl start firewalld