WD Photos App not seeing Shares

Please help me understand why I cannot see all the shares when using the WD Photos App on my iphone. I can upload and download from the “Public Folder” within the App but I have another Folder named Main Backup that I cannot. Inside the app it shows the Main Backup Folder but it says it has 0 photos. I know this is not true, there are thousands of photos in this Main Backup folder. How can I get the WDPhotos app to see these photos… Thanks

WD Photos only works with the Public Share.