In a March 4 update, Microsoft announced that Microsoft 365 web apps will get a new account switcher to allow users to run multiple signed-in sessions and switch between the accounts seamlessly. Not every Microsoft 365 web app supports the new feature, with Teams being a notable miss, but there’s enough there to make this a very useful feature.
https://office365itpros.com/2022/03/07/microsoft-365-web-apps/
