Sim Commander will automatically set the F1 2021 settings for you as long as your Sim Commander config for Steam is correct.
The only way to screw it up is to manually alter the settings in game. Please note that Sim Commander will not set these settings the very first time you run the game because the settings files don't exist at that time. The first time you run the game, F1 2021 creates the files that we alter the next time you run it.
This is what the settings look like in game after Sim Commander auto-configures them for you.