customize 3rd party vst screenshot


I just bought cubase 10 and super excited with the screenshot function of 3rd vst fx. I also use the external plugin function which allows my hardware to be used as vst plugin, but there is no screenshot available for those. I wonder if there is a way that I can manually save pictures of my outboard gears to my computer and if you can show me the path to where i should put these pictures?

Thanks so much!