Getting started
Run the visual checks, then select your own photo and adjust the crop and pixel dimensions. Save each wallpaper separately to Photos and set it in system settings. These checks do not diagnose faults. A selected photo may be downloaded by the system photo picker; delete working photos in the app. Photos copies remain until you delete them in Photos.
Contact
kkksss.support@icloud.com
Include FoldStart in the subject, along with the app and iOS versions, device model, steps that led to the issue and any error shown. Tell us whether you used folding input or the on-screen alternative. Do not send passwords or payment details.