i have used the client id and secret from the client application that i have created inside the admin tab. but when i try to do exchangeExternalAuthToken i am getting user not found in my console how can i fix this . Am i missing something... i have also attached the screen shot from my response and NOTE: 8103 is the port where i have run my meplum server locally

Do the Patients have ProjectMemberships? Were they created via the "invite" endpoint? https://www.medplum.com/docs/auth/user-management-guide#invite-via-api They need to have their identities created properly, per the user model - Patient resource itself is insufficient https://www.medplum.com/docs/auth/user-management-guide#background-user-model