Please try these:

1. Update your the current version of your Vobot

2. Check if you have mute your device

3. Check the [ Time/Alarm ]and [Daily Routine] setting on your Vobot and Alexa App

5. Check the vacation mode (Settings--General--Alarm/Timer Options--Vacation Mode)

6. Reboot your device

7. Check you Wi-Fi connection

8. Post the right music link