Listened for a few minutes: I'd tweak the EQ so that voices sound more pleasant. In fact the remote voice (is it Zoom or something similar?) sounds awful to be honest, but that's the shortcoming of this type of recordings. So you need to apply a different EQ to the remote voice: reduce the highs and slightly boost the mids/lows, but it may end up being tricker than that.

Ducking in general is an effect used a lot on radio: you have a background music that automatically "ducks" when there's a voice over it. In other words, background music gives way to the voice.