I'm using AWS Cognit, and when validating the access token I need to extract the email attribute to handle some migration cases between the app's database and Cognito.
but the issue is that I can't find the email in the token; instead, I get a username, which is a UUID.
is there any way to include the email to the access token (without making an extra call to pre-token-generation-lambda)?
This is not currently supported. Your backend can however send the access token to the Cognito user info endpoint to get the email.
You can then produce a useful claims principal containing the email. Then cache the extra claims for subsequent backend requests. See this code of mine for an example.