Hello,
FWCloud is a replacement for firewalld. Once you deploy FWCloud for your firewalls you no longer need to manage iptables rules using firewalld. In fact, once FWCloud is deployed in a firewall you must disable firewalld in order to avoid it from overwriting the rules set from FWCloud.
As you probably have firewalld/iptables rules already in place, you can use the import wizard of FWCloud to import all your current rules in FWCloud, check them in the GUI and once you are sure that the rules are ok, install them from FWCloud. After that step you must disable firewalld using systemctl.
Please, check this videos regarding the import wizard to get an overview on how it works on both single firewalls and clusters:
Single firewall import wizard
Clustered firewall import wizard
Would this work for your use case?