3634187 - Error "Missing required creator property 'userName'" during provisioning into IAS target (ias.api.version = 2)

User entities are provisioned from a source System (like "SAP Application Server ABAP") into a target system Identity Authentication with ias.api.version = 2.
The goal is to skip the attribute userName, as you don't want that the userName in IAS is overwritten by the entity of the source System. 

Attempting to ignore the userName in the transformation results following error similar like: 

"error=HTTP operation failed invoking https://<tenant ID>.accounts.ondemand.com/scim/Users with statusCode: 400, Response: {"schemas":["urn:ietf:params:scim:api:messages:2.0:Error"],"status":"400","detail":"Missing required creator property 'userName' (index 4)"}"

• Identity Provisioning Service (IPS)
• Identity Authentication (IAS)

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