Authorization for REST service in mendix

I have published a rest service in one project of mendix(with all three authorizations i.e. Username & password, Active session and custom). I am consuming that service from another project with a constant provide for the custom authorization it is giving me error saying Unauthorized, also when i am trying to debug the REST service debugger is not working.   Can anyone explain how to give custom authorizations. I have refered to and for publishing rest api and consuming it.
1 answers

Did you add key/value pair for authentication in the HTTP headers when using the call rest activity to consume the service? 
Also see this documentation for Call REST service and its configurations