Below are useful training resources provided by Nextiva:

Nextiva User Guide:

https://www.nextiva.com/downloads/guides/Nextiva-Voice/Business-Communication-Suite-User-Guide.pdf

Using the Nextiva App on your Smartphone:

https://www.nextiva.com/support/articles/nextivaappmobile.html

Using the Nextiva App on your Laptop:

https://www.nextiva.com/support/articles/desktop-app.html

How to Set-Up Voicemail:

https://www.nextiva.com/support/articles/how-to-set-up-voice-mail.html