cannot connect steam cd to account, already own windows versions

[thearn]

bought the game on steam to be able to play on the steamdeck without the headache of doing the xiv launcher, already own the windows version so i can't just add the cd key and steam button is greyed out.

[Final-Fantasy]

The Steam and Windows PC versions of the game are not compatible , you cannot have both or use both with your service account.

That means you can't login with Steam at all, you cannot add a Steam version to your SE account also.

So you'll have to stick to XIVLauncher.