Connecting ECC and S4 HANA with HCI

Hi Experts,

We have a requirement as below:

1. Purchase order from S4 HANA to ECC (Idoc) and

2. Invoice from ECC (Idoc) to S4 HANA.

We are using Cloud Connector to connect to the on-premise ECC system.

I am looking for detailed steps of configuration in ECC,CPI,SCC, and S4 HANA.

If anyone can help me with the detailed steps, that would be a great help.

Thanks in advance!

Aswini.