Depends on the embassy procedures. In Egypt, where I am from, once I was done with interview, I was given a paper and was asked to go to DHL office (within the same room), and gave him the papers, paid the fees and got a receipt.
For Ghana, you don’t register for a courier. When you are approved, they will give you a letter stating to go pick up your passport at the DHL office in two weeks. Some case it takes a little less time, others a little longer.