Think Bigger From Filmora User Guide

Fade In and Fade Out

To add Fade In or Fade Out effects to an audio file, you'll first have to place it on the timeline. Click the audio clip to gain access to the Audio settings panel and then drag the Fade In and Fade Out sliders to the right to add fade effects and set their durations.

find fade in and out maker

Drag the fade in/out bar to the right and you’ll see the effects from the timeline.

fade in and out maker in timeline