RingCentral For Salesforce - transfer to voicemail

We are using ringcentral for salesforce and there is only the 'transfer' feature vs. what you find in the main ringcentral app (ask first, transfer, transfer to vm). We need to transfer to voicemail from the 'ringcentral for salesforce' app. I have looked at all the various code options (*0+ext, ext+#) and none of them work. What is the correct code sequence?