You can get the ID of your Azure tenant by selecting Azure Active Directory -> Properties:
You can get the tenant ID of any domain by accessing https://login.windows.net/<domainname>.onmicrosoft.com/.well-known/openid-configuration.
For example, for this book, the domain name was handsonaksoutlook: https://login.windows.net/handsonaksoutlook.onmicrosoft.com/.well-known/openid-configuration.
For example, for this book, the domain name was handsonaksoutlook: https://login.windows.net/handsonaksoutlook.onmicrosoft.com/.well-known/openid-configuration.