You can just follow the same method of doing the CE upgrade (replacing the directory and moving the config and rrd over), but instead of using a new CE .tar.gz, you use an Observium folder checked out on another system with internet connectivity and copied over.

Only the MySQL database, config.php and rrd directory need to be retained.

Adam.

From: observium <observium-bounces@observium.org> On Behalf Of Daniel Marecki via observium
Sent: 27 August 2021 05:44
To: observium@observium.org
Cc: Daniel Marecki <dmarecki80@gmail.com>
Subject: [Observium] migrate from a Community Edition to a Professional edition - offline

Hello.

I've a local network not connected to the internet. I'm currently using CE edition. How can I migrate from a CE to a PRO edition offline?

Thank you for your answer. 

Best regards.

Daniel