Make sure your computer is fully patched with security and software updates. Outlook Mac build 15.27 (161010) or newer required for Outlook integration. Skype for Business 16.22 or newer is required for macOS Mojave. Make sure your computer will support Skype for Business: OS X El Capitan (10.11) or newer is required. I have read in several posts that I need to. Hello, I'm running the latest version of Skype for Business (SkypeForBusinessInstaller-16.28.0.175.pkg ) on the latest version of macOS Catalina (10.15.4). You also get to view other user profiles much better in Windows than in Skype for OS X.
I prefer to use Skype on my Windows partition, as Skype for Windows offers more customization options. All of the audio settings are turned up full on the skype settings and the strange things is that in the system preferences I can see that the mic is picking up sound and working fine. I've got a user who is trying to make calls using skype for business on a MacBook but when they do, the mic doesn't seem to be working. Ctrl+click and choose Start a Video Call to initiate a video call.
If the computer can support 10.11 or later, decide if you want to install the latest supported version for your computer. Go to Apple Support to check your computer's compatibility with the latest operating system.