Hi @RiyazuddinM
Identity attribute is a unique attribute for the target accounts. Example, For AD distinguishedName will be the identity attribute. Likewise, you should define identity attribute for your application. You can open your application → Configuration → Schema. Smaple screenshot is as below.
Similarly, Can you please share the screenshot ?
Also, can you let me know what are the operation you would require for this application other than aggregations and create account operation?
In your case, if employeeId is the identity attribute, you should get the value of it from response payload of Create operation. However, since your API is not returning that information, we need to identify alternate option.