You can access your organization's GTFS Schedule and Real Time data any time under Data Management -> Export.
Most third parties will appreciate receiving a URL instead of a zip file, simply click the copy button and share that directly.
You can paste this URL into a browser to download the zip file yourself or use the Export button to download a zip file to your computer.
NOTE: This is for GTFS Schedule and Real Time data for Spare Fixed Route. For exporting GTFS Flex data for demand response services, click here.