Hi,
As part of SAP process, there is functionality to crate ERP orders/Quotation from CRM Opportunity only. For other process type like Service Request etc. this functionality is still not available as we can not assign ERP transaction as followup to them.
But if you want to give reference then you can use Ext Reference field in ERP Order but unfortunately it will not have any link in Transaction History of the Service request.
Regards,
Ravi.