This program has a primitive audio editor. You can create a copy of the audio file, you can cut the file, or cut out a fragment at the fading points (minimum volume) of the sound and paste it into the main track also at the fading point with small steps to the main track, the program will automatically add a crossfade to the junctions.
This is a difficult and painstaking job. That's why I always edit audio in the professional Adobe Audition program. It has a wonderful Remix feature,
which allows you to lengthen and shorten the music to the desired length with an accuracy of up to a few seconds, which can be compensated by the length of the opening or ending credits.