Hi @Kay Khan ,
Great to know that this issue has been resolved and thanks for sharing the update here.
By the way, since the Microsoft Q&A community has a policy that "The question author cannot accept their own answer. They can only accept answers by others.". and according to the scenario introduced here: Answering your own questions on Microsoft Q&A, I would make a brief summary of this thread:
[How to get email from Microsoft graph api oidc/userinfo endpoint]
When request microsoft graph api
oidc/userinfo endpoint, the email field is not returned in the response.
This issue has been solved in other platforms and this issue occurs because the email field in the user profile is not set after you update the email field by editing the user's properties. The endpoint can return a response that has an email field.
You could click the "Accept Answer" button for this summary to close this thread, and this can make it easier for other community member's to see the useful information when reading this thread. Thanks for your understanding!