Hello @Abhay Chandramouli ,
Thanks for posting your query on Microsoft Q&A. As you have mentioned you the user's who are signed in would not be prompted to sign in again since SSO is enabled. In order to call the API kindly change the SSO status to "true" in Technical Profile to retrieve the extension attribute value metadata:
<IncludeInSso>true</IncludeInSso>
Please do let me know if you have any further queries in the comments section.
Thanks,
Akshay Kaushik
Please "Accept the answer" and "Upvote" if the suggestion works as per your business need. This will help us and others in the community as well.