Hi

I'm having my first go editing in Resolve as I've been massively won-over by the whole "all-in-one" solution with Resolve 15 but I'm having just one little issue.
I need to use a Waves plugin to do some precise filtering on some sound effects which requires some detailed automation. I can record the automation fine by setting it to record and just moving the knob but it's a bit fiddly doing this with the mouse so I'd like to draw the automation in with keyframes.
I can see the track drawing onto the screen in a green line over my waveform but I can't figure out how to go in and edit it.
Could some kind soul let me know where I'm going wrong? I'm sure it bust be possible, I just must be being dim

Cheers in advance!