Defaults for SameSite by default cookies and Cookies without SameSite must be secure

David Lowy 

I think you can get information here.

- edge://flags/

- Site compatibility-impacting changes coming to Microsoft Edge
https://docs.microsoft.com/ja-jp/microsoft-edge/web-platform/site-impacting-changes
This change is happening in the Chromium project, on which Microsoft Edge is based. For more information, including the planned timeline by Google for this change, please review the Chrome Platform Status entry. Based on user and developer feedback, the Microsoft Edge team is shipping this feature in Microsoft Edge at the same time or later than Google.