Google Voice would be a paid service for district accounts. (There was a time in the past when it was free and there may be some staff with legacy accounts). It can be obtained as a free service if you have or create a personal gmail account. That is our recommendation at this time; the district does not presently have a funding option to support all of the potential requests from staff.
Here are Google's notes on creating an account: https://support.google.com/voice/answer/115061?co=GENIE.Platform%3DDesktop&hl=en