if you had done what was said in the docu, then you are probably able to tell in detail the settings that you had done for the delivery item category.
And how do you actually want the batch being populated? if this inbound delivery is for a purchase order, then a batch is created with goods receipt, or by clicking the Create batch button in the delivery.
It is unusual to receive to existing batches which have been received before, but if that is your case, then batch determination should be able to find a batch according to your definitions