How to use the background music function in QT voice

How to use the QT voice background music function:

The QT voice background music feature allows the user to simultaneously output local playback of the background music in the voice.

Click

button is selected when the button is

Indicates that the background music feature is enabled, and the locally played background music is also output at the same time as the voice.

After entering the room panel, the "Background music" button is available if the sound card supports the mix feature, and the current version does not support standalone sound card users under Win7 and XP