Make sure you have the right MSI package file linked in Kace.
then copy the following comand line... it works for me (version 3.0.08057)
anyconnect-win-3.0.08057-pre-deploy-k9.msi /qn
anyconnect-win-3.0.08057-pre-deploy-k9.msi /qn
View inventory records anonymously contributed by opt-in users of the K1000 Systems Management Appliance.