Let's take a fair common vocal tracker, where some parts of the take are louder (peaks) and some parts are quieter.
Before adding any FX to the track, let's first level out the take, so that the take has generally the same volume level throughout. Select envelopes and checkmark volume (Pre-FX).
Now, on the newly added envelope track, hold down the Ctrl button (Windows) and draw to bring up the volume on the quiter parts and to bring down the volume on the louder parts, so that the take is generally the same volume throughout.
Now you can add a bit of compression to the track to further level things out. Here are fairly good settings to get started with.