Fortigate offline packages updates

Hi

We have fortigate firewalls to be installed and managed by Fortimanager, they will have internet access, so the licenses and packages updates will be done offline, I have two questions on this regard;

- What is the schedule of packages updates in fortinet portal, like every quarter, and how to know about new updates?

- Is there specific configuration for fortigate to get updates from fortimanager (rather than the Central-Management settings)?

"As the below document page-8 states about some other steps, but I dont know if they are required"

https://docs.fortinet.com/uploaded/files/2153/LicensingIsolatedFortiGates.pdf

Thanks