Use VideoStudio's "sound track" and "music track" to create, the steps are as follows:

1. Use this software to open the recording file you want to edit.

2. Drag the recording file to the "Sound Track".

3. Open the background music file according to the first step.

4. Then drag the background music file to the "Music Track".

5. Then click Share on the menu bar and select "Create Sound File".