FAB No labelling required

My product (bag) has not any kind of code on it, if labeling not required, how do they in the warehouse know which is which in a mix SKU in one box?

I do not have the issue when using the ‘old workflow’. It always happens for ‘Send to Amazon’ which would be the only option in Sep.

I checked some old topics but still could not get head around. my amazon barcode is the preference.

Any one can help? Thanks.