Epic on FHIR backend OAuth2.0 with Epic Community member authentication server

[Ali]

Hello everyone,

We are trying to connect to an Epic Community member's Epic instance using the Epic on FHIR backend service. The community member that we are working with is not familiar with the Epic on FHIR process and this is our first time using Epic on FHIR. Currently we have created an Epic on FHIR App, uploaded our public key, and successfully tested it with the Sandbox (successfully got the access token and made API calls to the Sandbox environment). We then instructed the community member to send a request to use the App and I have accepted their request and uploaded the public key. Given that the Epic community member does not have experience with Epic on FHIR and we are new to the process, we are unsure what instructions to give to the community member in order to configure the authentication server in order to allow us to successfully obtain an access token using JWT. Does anyone have documentation that we can give to the community member for instructions on giving us the ability to successfully call their authentication server? Also, are there any steps that we are missing? Currently when I make a call to their authentication server, I get the {'error': 'invalid_client', 'error_description': None} error.

Thank you

[sibin c sebastian]

can you help me with the steps to fetch the token??