A packaging can not be purchased at a ServicePoint from DHL Parcel, but it is an option that will be available soon. 

Each shipment (box) will need to have a single label. If you want to ship two different shipments even if they are delivered to the same address you will need to create a new label here 

If you are a customer with a DHL account, you can request your collection through the Customer Area

If you are a particular one, once the shipment is properly packed and with the sticky label, bring the package to a collection point. Check your schedules and the nearest one here.