The following commands can be used to configure IPFIX flow reporting on Ubiquiti routers. First, enable IPFIX, or Netflow version 10 as it's shown in the configuration menus in EdgeOS.
set system flow-accounting netflow version 10
Then tell the router which interface to collect flow data from.
set system flow-accounting interface eth0
In this case we're collecting IPFIX flow data on interface eth0.
Next tell the router was IP address and port to send IPFIX flow data to.
set system flow-accounting netflow server 192.168.90.195 port 4739
In this example the flow collection server is at 192.168.90.195 and listening for IPFIX flows on port 4739. Be sure to commit the configuration, and if everything is working properly save it so settings will be applied when the router reboots next.