Based on the comments there's a few things going on, but there are a few relevant things:
- AAD Provisioning doesn't currently include custom values in the "schemas" attribute even if an attribute from a custom schema is being used. The core and enterprise extension user schemas are always passed, but the urn:sap:cloud:scim:schemas:extension:custom:2.0:User schema is not being included.
- The screenshots are hard to read, but it looks like the error being returned may be referencing the fact that an attribute was included in the payload but the relevant schema was not included in the schemas attribute.
- AAD Provisioning doesn't currently support custom SCIM schemas that don't align with the pattern urn:ietf:params:scim:schemas:extension:CustomExtensionName:2.0:User:CustomAttribute. The two bolded sections that start with Custom can be changed, but otherwise that pattern must be used. This is overly restrictive behavior in AAD Provisioning, and the SCIM standard does allow for any URN to be used. There is a development item in our backlog to relax this behavior, although I cannot share an ETA publicly at this time.
- Finally, as you mentioned, it appears that this SCIM endpoint is deprecated by SAP and they have a new one. It looks like the tutorial published in the Azure AD/Entra ID documentation is outdated. I'll pass a note to the team that manages this to see if we can get the tutorial refreshed.