Unable to copy rules to SteamOS Udev folder

[Reborn627]

I'm a total noob. I've installed oversteer in SteamOS, using a flatpack and when trying to run the commands after install, it falls to copy the 3 rule files to the Udev/rules.d folder. It looks like these folders are locked and I don't know the proper command to unlock them. Can anybody assist with this? If like to get my Thrustmaster TMX pro working on my Steam PC.

Thanks in advance,
Ray