You can use Animaze while Steam is in Offline mode. However, Animaze requires an internet connection to function. As long as the PC running Animaze is connected to the internet, Animaze will work (even if Steam is in Offline Mode).

If you stream with a 2 PC setup, you can run Animaze on one PC with Steam in Offline Mode and run your game on the other PC with Steam in online mode. Both PC’s should be connected to the internet.

How to set up Steam in Offline Mode:

1. Start Steam in Online Mode

2. Make sure that all game files are updated

3. Go to Steam > Settings > Account, make sure that the "Don't save account credentials on this computer" option is not selected

4. From the main Steam window, go to the Steam menu and select “Go Offline”

5. Click “Restart” in Offline Mode to restart Steam in Offline Mode

Most games require an initial start-up while connected to the Steam Network before you can switch to Offline Mode. If the game’s status shows “100% - Ready”, but you receive the message: "This game cannot be started in Offline Mode" when you try to play it offline, it means that the games or its files need to be updated.

While Steam is in offline mode, you can't access any Steam features, including purchasing coins and subscriptions. 

For more information on Steam Offline mode, see this article from Steam.