PP Confirmation with serial number

Hi Gurus

I try to confirm Production orders through serial numbers.

I customized the confirmation profile in OPK0. i am now able to enter a serial number in CO11N

If I enter only serial number in CO11N . it is not sufficient for SAP. System requires production order number and Operation.

And this message

Enter confirmation number or order/sequence/operation/suboperation

Message no. RU001

I want to confirm only with serial number is this not possible in SAP?

Best Regards

Emre