How does Apple download ringtones for mobile phone calls?

when using an apple phone, you should download and set the ringtone. let's take the iPhone 11 as an example.

tools/materials: iphone 11, ios 14.4.12, library band 4

1,? Open the music software in your phone, find a favorite song, and click on the three dots on the right.

2. Click the setting ringtone below.

3. Save it in the library band that comes with the iphone.

4、? Open the library band and press this music to see the pop-up window. Click the * * * at the bottom to enjoy it. Click Set as Ring Tone, and click Continue.

5. After compression, click the one indicated by the red pointer to set it successfully.