Create Communication System to Connect to SAP Cloud Platform ABAP Environment.

Open SAP Cloud Platform Cockpit and select your global account.

Click Subaccounts.

Select your Cloud Foundry subaccount.

Go to Destinations and click Download Trust to get the certification.

Open SAP S/4HANA Cloud system as an administrator.

Go to Identity and Access Management and select the Maintain Business Roles tile.

Click New to create a new business role.

Define your business role and your business role ID.

Select Assigned Business Catalogs tab and click Add.

Search SAP_CORE_BC_COM, select it, apply the change and click OK.

Open SAP S/4HANA Cloud system as administrator.

Go to Communication Management and select the Communication Arrangements tile.

Click New to add a new communication arrangement.

Select SAP_COM_0008 as scenario and give your arrangement a name.
SAP _COM_0008 as the communication scenario is needed to set up the communication with SAP Cloud Platform as business partner.
Click Create.

As a result you get following display. Click New to create a new communication system.

Enter a system ID and system name.

You need to switch to your SAP Cloud Platform Cockpit to set your host name.

Open SAP Cloud Platform Cockpit and select your global account.

Select Subaccounts.

Select your Cloud Foundry subaccount.

Switch to your space.

Click Service Instances and select your own service instance.

Now you can see your service key. Inside your service key is your instance URL.
Your instance URL is structured as following:

xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.abap.eu10.hana.ondemand.com
Copy your instance URL without https:// to paste it as host name in your communication system.

Switch to your SAP S/4HANA Cloud system, open your communication system, paste your host name and click save.

Enter DUMMY as logical system and business system. Don’ t click save yet.

Check enabled in the OAuth 2.0 Identity Provider area. Upload the certificate
you downloaded in step 1.4 from your SAP Cloud Platform Cockpit.
Copy the common name (the string after CN=) and paste it into the Provider Name field.

Don’t save yet.

Choose + in the inbound communication area to add a new communication user for inbound communication in SAP S/4HANA Cloud.

Choose New User.

Enter your communication system name as user name and description. Click Propose Password to generate a password and
Click Create.

Click OK.

Choose + in the outbound communication user area to create a outbound communication user.

Select SSL Client Certificate as authentication method and Default Client Certificate as certificate type.

Choose Save to save your communication system.

Edit your communication system and select OAuth 2.0 in the inbound communication area.

Select Default Client Certificate in the outbound communication area.

Deactivate all outbound communication services. The outbound services aren’t relevant
for outbound communication from the SAP Cloud Platform ABAP environment to SAP S/4HANA Cloud
Click Save.