It's configurable via a simple json file.
Example config:
{ "image_list": [ "/ISO/Linux/archlinux-2020.10.01-x86_64.iso", "/ISO/cn_windows_10_enterprise_ltsc_2019_x64_dvd_9c09ff24.iso", "/ISO/Win10PE.iso" ] }
or:
https://www.ventoy.net/en/plugin_control.html
And something like:
{ "VTOY_DEFAULT_SEARCH_ROOT": "/ISO" }