I am creating an API for our service and would be used to display user details like the subscription info and such after they log in.
But is it better if I use the token from Universal Login or collect the user info, pass it to my API and authenticate the user there?
It sounds like this is data that only logged in users should see. It’d be best to use the Access Token that is issued after authentication. The frontend will use the Access Token as a bearer token with each API request. You can use an Auth0 SDK in your API to validate the Access Token.