Which S4 HANA Cloud system do we need to use?

Hi Experts,

We recently purchased S4 HANA Cloud system.

where we received two provisioning systems (S4 HANA Cloud Customizing tenant & Development Tenant).

we need to integrate this with CPI-->Subscription Billing.

Which system do we need to use S4 HANA Cloud Customizing tenant or S4 HANA Cloud Development tenant?

Could you please help us?

Could you please