Why can’t I use SMS ringtones on 91iPhone?

If you have music on your phone, just click iPod management, select the music, set it as a ringtone, and you can directly create a ringtone and upload it

There are also videos on the Internet that solve this problem. Operation demonstration

You can just search "Longyun Mobile Network" on Baidu. There is a video viewing section

Follow the online videos to teach you how to operate and you will be able to solve the problem smoothly. Because

There is a very detailed introduction in the video. About “Why can’t SMS ringtones work on 91 iPhone?”