if you are talking about the PEER NGA Records EVT option, the code that actually downloads the records is part of the Frontend of the application (the reords are obtained when you press the 'secet Records' button). Once downloaded, the backend code iss just using the Multiple PEER application running in the backend. At present this means you have to go through the EE_UQ tool to download the records. An option for you is to edit the saved EE-UQ file directly with whatever options you want, the load this file in EE_UQ and then hit the Select Records button to download the files.
the code for downloading the code is in PeerNGAWest2Client in the following folder
https://github.com/NHERI-SimCenter/EE-UQ/tree/master/EVENTS/peerNGA