Salesforce Exceptions

Salesforce

System.DmlException: Insert failed. First exception on row 0; first error: FIELD_INTEGRITY_EXCEPTION, field integrity exception: [] Salesforce PSR Creation

Error Message:{        "message": "field integrity exception",        "errorCode": "FIELD_INTEGRITY_EXCEPTION",        "fields": []}The creation of PSR(PendingServiceRouting) for external or queue-based routing from apex is not supported. It is applicable only for Skill based as ....