To be able to use the new Inbox Calling feature, you will need to allow microphone permissions for your browser.
If you have previously blocked these permissions, you will need to go into your browser settings to enable them to be able to call your contacts from the Referrizer Inbox.
Chrome
https://support.google.com/chrome/answer/2693767?hl=en&co=GENIE.Platform%3DDesktop&oco=1
Safari
https://support.apple.com/guide/safari/websites-ibrwe2159f50/mac
Firefox
https://support.mozilla.org/en-US/kb/how-manage-your-camera-and-microphone-permissions