Employeecentral payroll Initial user.
"The CUST_INIT user, provided to you, should only be used for initial customer user management. Design user roles in DEV only, and transport these to QA and PROD in a controlled manner. SAP_ALL should not exist in QA and PROD systems."
Is CUST_INIT is SAP provided at the time of license to business or it created when we rasised CAR request for Provision access.
How we get the system details and CUST_INIT psw.
In me.sap.com (former Lauchpad) You can see the systems you have (also the code and link to it).
For the CUST_INIT user, you can request a reset for it if you don't have the details:
3099835 - CUST_INIT Password Reset for Employee Central Payroll | SAP Knowledge Base Article