Steam Account - Need help for users that don't actually have FFXIV on their steam

[whiskeybravo]

You can't apply a normal key to an account that has a Steam key on it.

Then what does this mean?

For users who possess a Square Enix account with multiple service accounts (specifically ones that have both Steam and Windows licenses)

Not arguing, I just assumed it was like ps4/pc where you can have a license for both and play on either, but only pay 1 sub. If that's not the case then it sounds like he's referring to separate subscription (service) accounts.