To set a custom ringtone on an iPhone, you can follow these steps:
1. Choose the song or audio file you want to use as a ringtone and make sure it is in the correct format (AAC file with .m4r extension).
2. Connect your iPhone to your computer and open iTunes.
3. Select the song you want to use as a ringtone in your iTunes library.
4. Right-click on the song and choose "Get Info."
5. Go to the "Options" tab and set the start and stop times for the ringtone. Make sure it is no longer than 30 seconds.
6. Click "OK" to save the changes.
7. Right-click on the song again and choose "Create AAC Version." This will create a new shorter version of the song.
8. Locate the newly created AAC version of the song in your iTunes library.
9. Right-click on the AAC version and choose "Show in Finder" (on Mac) or "Show in Windows Explorer" (on Windows).
10. Change the file extension of the AAC version from .m4a to .m4r.
11. Go back to iTunes and delete the AAC version of the song if you no longer need it.
12. Drag and drop the .m4r file into the "Tones" section of iTunes.
13. Sync your iPhone with iTunes to transfer the custom ringtone to your device.
14. On your iPhone, go to Settings > Sounds & Haptics > Ringtone and select your custom ringtone from the list.
Your custom ringtone should now be set on your iPhone.
