Enable single sign-on (SSO) for Office Add-ins
The Single Sign-on API is currently supported in office.js preview.
Single sign in is now in product/GA! Thanks for your suggestion. Let us know if you encounter any issues by going to https://github.com/OfficeDev/office-js/issues and opening a new issue. Thanks, Microsoft 365 developer platform team.
Saber Karmous commented
The SSO API has been in preview for a while now. Is it clear on what the estimated release date is?