Getting username from Outlook app in Bash on MacOS devices

Question

I'm having an issue where I'm writing a Bash script, and I need it to retrieve the current User Principal Name used with Outlook or Mail account to send emails.

Script needs to configure a an app that changes behavior based on the user that logs into it. No password is needed, just the UPN used with emails.

If I use

userName -string "$(whoami)@INSERTYOUREMAILDOMAIN.COM"

result: [email protected]

I only get the local user profile name, which is not the desired result. Can I retrieve the UPN used with Outlook or Mail apps?

Basically, get the Office 365 user ID

In Windows it's very simple.

whoami /upn

I'm not really used to working with MacOS in general, so it's not as handy as Powershell, or I may be missing something :/