Update OID4VCI configuration file in configuration documentation

api_docs/configuration.md

@@ -35,7 +35,7 @@ You can find example test private DS keys and certificates, for country Utopia (
 
 ## 3. OID4VCI configuration 
 
-For configuring the installed [idpy-oidc](https://github.com/IdentityPython/idpy-oidc) and [openid4v](https://github.com/rohe/openid4v) libraries, you need to change the following parameters in the ```app/app_config/oid_config.json``` configuration file:
+For configuring the installed [idpy-oidc](https://github.com/IdentityPython/idpy-oidc) and [openid4v](https://github.com/rohe/openid4v) libraries, you need to change the following parameters in the ```app/app_config/oid_config.py``` configuration file:
 
 - port