Support Entra B2B users (aka guest/external users) to login to the Pac CLI

[joem-msft]

Problem
Many Power Platform products (Power Apps, Power Automate, Dataverse, etc) support Entra B2B users (aka guest or external users).
As of today, these users are not able to successfully login to a target tenant via the pac auth create command. While the --tenant can be specified, it seems like this causes authentication to fail to launch.

B2B users are essentially blocked from using the Pac CLI.

Proposed Solution
Fix the pac auth create command by ensuring the existing --tenant argument is used to indicate the tenant ID to use for user account logins. The command will use this tenant Id to generate the authority endpoint for starting the login flow, which will then allow the guest user to enter their home tenant credentials, for logging into the target tenant.

[joem-msft]

Created this idea in order to allow customers to vote and indicate whether this is a scenario that is useful.