There are image use issues that may make downloading images in bulk not allowed, or at least difficult. Everyone can set the licensing options to their own preferences on iNat, so you’d have to go through and pre-filter the images to be only those with the appropriate use license.
@pisum’s comment here in the Preferred ways of batch downloading a subset of the iNaturalist data? thread may provide some insight and assistance.
This may also be a useful thread: Download iNaturalist images from GBIF using R