auth.getUser() returns the details available under /userinfo endpoint on the authorization server through which the user got authenticated and authorized, as described here.
If you would like to publish other details also on this /endpoint, please do the following:
• navigate from your Okta tenant to Admin >> API >> Authorization Server >> your authorization server
• under Claims tab, add new claims with the user’s profile values and, under “Include in token type”, select “ID Token” and “Userinfo / id_token request”