Hello Stefan ,
In the Service Confirmation , we do not have option/functionality 'Submit ->Send Confirmation to Customer'(similar as in Service Order).
***Please See:=>
For 3rd party repair scenario, the Service Confirmation created at Supplier Company's service center trigger an automatic confirmation by XML when service confirmation is released. It is for there automatic
outputs that the tab is present in service confirmation.
Hope it answers your query.
Best Regards,
Ankush Pashine.