If you only have a selection of photos from your library showing when uploading items (or none), then you've likely allowed Yaga access to only selected photos or none at all. Please check your phone Apps settings to make sure you're allowing Yaga to access your whole gallery.
Please make sure your photos are not in HEIC format, as this file type cannot be uploaded to listings.
You can change the image format in your device settings (Settings → Camera → Formats → Select “Most Compatible”). Alternatively, you can take a screenshot of the photo, which automatically converts it to a compatible format.
If you need further assistance or have any questions then you can contact Yaga support by submitting a request below.