change gain option in audio editor has vanished?

There used to be a funcion to "change gain" in the audio editosr drop down menu tabs. If you clicked on any region in the arrange window it would open the audio editor at the bottom of the arrange window. That option now seems to be gone. When I look online for info Apple has a tutorial page that displays the exact "change gain" window I'm looking for and states that to acces this function you need to use the functions drop down tab. Well the only dropdown tabs I have in the audio editor are Edit and View. Both of which don't have a change gain option.

Am I missing something here?

By the way, some online tutorials suggest turning on FlexTime which will give me a gain slider to the left of the audio editor. Well when I try and use that gain slider, there is no change in my files volume! What's up with this?

Thanks