You can download it from the AppStore, or you can connect your phone to iTunes on your computer to download it.

1. First download the latest itunes. After downloading and installing, open itunes, as shown below:

2. Find the file in the top menu bar of itunes and click Exit. In the drop-down box, as shown below, you will see two options, with two forms of addition:

1) Add files to the database: add a single file or multiple files (Ctrl+the selected file) Yes)

2) Add the folder to the library: Add all the music files in the folder, similar to creating a file in the library.

After adding, if the format is incorrect, it will be automatically converted. Then you can see the successfully added music in the music options