it is a medical certificate that you get from the hospital. This is generally given to next of Kin. Ring the hospital to let them know who will be collecting it They can advise you if any issues. The medical certificate is taken to the registry office to register the death, which is when you get the death certificate. This can be done by next of Kin or relative or someone who was there at time of death or person arranging funeral.
Sorry for your loss.