In order to add an audio file to Movavi Clips project, please take the following steps:
1) Open your project in Movavi Clips app and tap on the“Audio” icon. That is the first one right above the video track:
2) Tap on the purple “+” icon, it will redirect you to the tab "Add music":
There, you can select the music from either your phone gallery or the Movavi Clips built-in library:
If you cannot find your music here, please check this article.
3) Select the audio and tap 'Select'.
Thus, the music will be added to the timeline: