Hello rasp_nav,
If your Shake is connected to our network and transmitting live data, you can download your instrument response from this link:
https://data.raspberryshake.org/fdsnws/station/1/query?level=resp&network=AM&station=XXXXX
Just change the final XXXXX to your Shake name (for example, R1234) and then save the file as .xml.
Otherwise, you can check your Shake version (either on the white label close to the leveling bubble, or, by providing the logs of the Shake -instructions here: Please read before posting! -, I can do that for you) and download the appropriate metadata files following these instructions: Metadata - Instrument Response Files