Unable to set off-grid mode in local mode

[Scrub000]

python -m pypowerwall get -host 192.168.1.69 -password AVRDB
python -m pypowerwall set -gridcharging off

It says I do not have a Fleet API set-up, but I politically oppose using the cloud.

How can I use my Powerwall 2 completely locally? Are there any hardware or software modifications I can do? Is it possible to roll back firmware?

Discovered 1 Powerwall Gateway(s)
         192.168.1.69 [1152100-14-J--CN323065G4J05Q] Firmware 25.18.2 e1f565d8

Is it also possible to block the Powerwall 2 from ever reaching the internet? I want to prevent any additional firmware "upgrades". I'm hoping, if I can lock the firmware for a few years, it may be possible to exploit the PW2 and use it fully locally for all get and set operations.