There are two steps to add the music you want:

Method 1

1. Open the Paipai APP and click on the avatar in the upper left corner.

2. Click the settings button on the left.

3. Enter the settings, click to turn on the background sound effect function, and select the music you want to add.

Method 2

1. First download some songs from Baidu.

2. Put it into the "My Music" folder (because this folder is the default for iTunes, so the songs you don't want to add should be deleted from here).

3. After putting the songs in, open the itunes library.

4. Enter the "Music" section, click "File" in the upper left corner, and select "Add Folder to Library".

5. Then select the "My Music" folder, and then itunes will automatically add the files to the library, and you can listen to the songs on itunes.