? About adding free dining to an existing reservation

[yooperfan]

First, I made my ressie because I wanted to guarantee a preferred room not really for dining. My question though, I’ve heard people say you can add free dining to your existing ressie if your ressie has a modify button. Is that the same as a change teservation button? Also, if free dining comes out will it be listed under dining choices online and will there be a code you have to apply in dining?