firewall License || virtual firewall || HA test

You just register the serial number, then you get 30 days of trial. Then you put them in HA.

Please do not do this! 
Because if you start a Trial, the second appliance gets a eval for Base as well! 
That can cause massive issues. 

Instead: in the wizard before registration, use the "connect to HA" option. Only available for virtual appliances. 

now i m confused how to do this ?

Install your primary as usual. 

The AUX appliance, install it in KVM. Start it, access it via 172.16.16.16:4444

You will find in the wizard on page 1 an option on the top right corner: https://docs.sophos.com/nsg/sophos-firewall/19.5/Help/en-us/webhelp/onlinehelp/HighAvailablityStartupGuide/VirtualHA/HAConnectSpare/index.html#configure-ha-on-primary

This Guide is the one for you. 

Sorry for that, I did't realize these are virtual appliances. Follow the advise from Lucar Toni, please.

in the wizard before registration, use the "connect to HA" option. Only available for virtual appliances ----where I will get this option

in the wizard before registration, use the "connect to HA" option. Only available for virtual appliances ----where I will get this option

You only get this after installing the firewall and DID NOT register it yet. See the Guide above.