Manual signature updates while air-gapped?

Hi all,

I formatted a fortigate with 6.4.6 and air-gapped it for testing. I'm trying to update the onboard AV/IPS signatures. I've done this before on previous versions with no problem. I double-checked the directions at https://docs.fortinet.com/document/fortigate/6.4.6/administration-guide/200702/manual-updates and the interface I see doesn't have the buttons to to "upgrade database". Does the firewall need to "phone home" successfully before it will allow manual signature updates?