Can I get Google Voice?

Unfortunately Google Voice is a paid service so it is not available to Google Workspace domains for free.  However, you should be able to set up a free Google Voice account with a free personal Gmail account if you have one. 

Paid Add-on: Google Voice for business requires an active Google Workspace account plus a monthly per-user Voice plan.
Tiers: Plans cost $10 (Starter), $20 (Standard), or $30 (Premier) per user, per month.
Free Version: The free version of Google Voice only works with personal, consumer Gmail accounts and is restricted to personal use. Using a free personal account for commercial purposes violates Google's terms of service.