Yeelight without internet on Mi Home app

I have 6 Yeelight Color bulbs v2 lamps connected on Mi Home app. How can i use offline if my internet goes down?

You can’t use the app while offline.
You can turn on/off lights with regular switch.

Lifx bulb works with or without internet. I think yeelight should do it as well with their app.
For yeelight you’ll need to use the Yeelight toolbox available for Windows operating system. It need the prior activation of the LAN control from the Yeelight app

If your local network works you can control it with telnet from command line on a PC or smartphone. See Yeelight WiFi Light Inter-Operation Specification

If you enable LAN Control in the Yeelight app (not Mi HOme app), you can control your bulbs locally via Wifi connection using Yeti app.