There is no voice output through VLC playing music by inserting a USB UGreen sound card

We got a sound card to insert into USB of TX1, and want to test voice output. Moreover, a VLC media player is download to play a MP3 song. But the VlC player logged with “PulseAudio server connection failure: connection refused”.

Whether need a sound card driver or something wrong?

I have got sound from VLC media player, and set Tools/Preferences/Audio Settings, Output model: alsa audio output, device: USB Audio Device, USB Audio default audio device.