Go to Dashboard -> Wpperks -> Geodirectory -> Media Library
Setup media library that you want to show
Click Save Changes
After that go to the CPT Listing on the Backend. Make sure the Add Image Button shows on the right side of the page
You can add images to the listing using the Media Library
If you want to change it via the frontend you can go to /add-listing/ then make sure the Add Images Button is show, Same as above, you can add an image in the Media Library
Images that have been added can be saved as if you were adding images by default which belongs to Geodirectory