While onboarding a merchant in production, make sure you are providing correct details.
We do a PAN verification of the PAN number provided by you in the Onboard User API and match the name returned in PAN verification and the name coming in API. So please do enter valid PAN number and it should be of the same merchant/user whose name you are giving
To generate secret-key and secret-key-timestamp, refer to - Authentication
In the response you will be getting a unique user_code for your onboarded merchant.