@Ramalingam Velappan , If you want to view or change the Name ID format which will be used in token, you can navigate to Azure Portal > Azure Active Directory > Enterprise applications > All applications > Select your NonGalleryApp > Single sign-on > SAML-based Sign-on > Edit User Attributes & Claims section > Click on Unique User Identifier (Name ID).
However, if you really need NameIDFormat tag in the metadata, please post a feedback at https://feedback.azure.com. This feedback portal is monitored by product team for product enhancements.
Please "Accept as answer" wherever the information provided helps you to help others in the community.