You have to specify which content is being enabled by assigning a SAP system alias. You can also activate framework services such as metadata.
In transaction SPRO open the SAP Reference IMG and navigate to: and click on the Activity icon.
From the Manage SAP Gateway GSDO Groups table, select the entry for your scenario.
In the Dialog Structure section, double-click Assign SAP System Aliases.
Choose New Entries.
In the SAP System Alias column, use the value help to select the system alias that points to the SAP system on which the service is to be executed.
In the User Role column, enter a role that contains users who need to use the content scenario in the system of the SAP system alias.
Leave this column empty if all user roles need access.
Save your settings.
Double-click Manage SAP System Aliases and ensure that the Active checkbox is selected for the SAP Gateway GSDO group you created for your content scenario.
If you want to consume metadata information, proceed as follows:
Create an RFC destination and an Alias for LOCAL which points to the SAP Gateway system itself.
Use built-in SAP Gateway services: the GSDO group is called IWF_FW_SERVICES and it already contains the required GSDO. Therefore, you only need to maintain the SAP system alias. In this case assign LOCAL.
As a result you can fetch a list of all Service Documents, for example, http://<server>:<port>/sap/opu/odata/IWFND/MetaDataProcessing/ServicedocumentCollection/?$format=xml