having trouble to download OAP file through Lifetime Api

Hi

i am creating one timer.with the help of timer i have to download all .oap file for backup up purpose.for that reason i am using Lifetime API.below SOAP service i am using

application list i am getting but i am unable to download running version.



application key and authentication  i know but what is environment key.can you plz help me to resolve this?everytime i am getting 0bytes data.

i can download .oap file.but i want to download all .oap file in our on premises server.how to upload that .oap file to on premises server for backup purpose.