Why can’t the songs downloaded on Huawei mobile phone wp8 be used as ringtones for incoming calls?

wp8 is limited by the system. If you use uc to download songs, they can be used directly as ringtones. Long press the song in the download list, and a drop-down menu will appear. Just select it

You can also use a data cable to connect to the computer. The default is a USB flash drive. Just put the file you want to use as a ringtone in the Ringtones folder

Just select it when you start the computer