firewalld binary package in Ubuntu Focal armhf

 firewalld is a dynamically managed firewall daemon with support for
 network/firewall zones to define the trust level of network connections
 or interfaces. It has support for IPv4, IPv6 firewall settings and for
 ethernet bridges and has a separation of runtime and persistent
 configuration options.
 It also provides a D-Bus interface for services or applications to add
 and apply firewall rules on-the-fly.

Source package