I have few questions.
1. When we create a custom fiori app using SAP Fiori Elements (using RAP for backend) in BAS, where do we deploy the app? In S/4HANA ABAP cloud environment?
2. When creating the adaptation project in BAS, which system should we select? I am assuming that the SAP delivered standard fiori apps are deployed in S/4HANA ABAP cloud environment.
Since we don't have an actual S/4HANA public cloud system yet, I just thought maybe I can try to use the BTP ABAP environment and use some existing apps and I got this error. I am just wondering if I will get this error as well when I select the S/4HANA ABAP cloud environment?
After creating a custom Fiori application using SAP Fiori Elements and RAP (Restful ABAP Programming) in BAS (Business Application Studio), you would indeed typically deploy this app to an SAP S/4HANA ABAP cloud environment. Alternatively, this could also be deployed to an on-premise system if it supports the right version of netweaver and S/4HANA.
When creating an adaptation project in BAS, you should choose the system where your custom app would be running. In general, it would be the SAP S/4HANA ABAP cloud environment or it could be an on-premise system if your app would be used in that context.
Regarding the error you're encountering, it's hard to speak to directly without more information about the specific error message you're seeing. However, broad speaking, BTP ABAP environment and S/4HANA (Cloud or On-premise) are different environments. SAP BTP ABAP Environment (formerly known as SAP Cloud Platform, ABAP environment) is a PaaS for ABAP, whereas SAP S/4HANA is an ERP solution.
If your Fiori app is using any S/4HANA-specific features/functionalities/tables, and your selected system is BTP ABAP environment, then the error may persist as the S/4HANA functionalities may not exist in BTP ABAP environment. In general, if you're developing a Fiori app specifically for S/4 HANA, it would be best to develop and test in an SAP S/4HANA environment, be it cloud or on-premise.
I hope this clarifies.