Veyon add-on : network-discovery

[Bevito]

Dear Veyon Community,

We are interested in acquiring network-discovery addon, to help us managing RDP sessions (used with Apache Guacamole).
I just want to know if we can test it ?

We installed the add-on on Veyon Master (veyon-addons-4.4.2.22-win64-setup.exe), and set-up network discovery to scan a range of IP addresses ( a classroom IP addresses)
We don't see a difference on "Locations & computers".
Do we have to remove computers added with the Network object directory backend Builtin (added with veyon-cli command line) ?

Do we have to install the add-on on veyon clients too ?

Thanks for your help and your advice.

Best regards.