Accessing Graph API from Teams apps

I need some help around accessing graph from Teams apps. We have some apps running in teams which are being used by our employees. The app will be providing functionality through graph API. Until now, we've been using client_credentials flow for getting access to graph, but we want to move away from this approach and achieve the following:

1. Access graph api as the logged in Teams user who is running our app.

2. The users should not be asked for any credentials, the token should be obtained in the back-end on behalf of the logged-in user.

Is this possible to achieve?