How to save photo from filesystem to camera roll in iOS

I finally save image file to

// /E4A79B4A-E5CB-4E0C-A7D9-0603ECD48690/Library/NoCloud/cdv_photo_003.jpg

but it’s not shown on my camera roll on phone!

I used many plugin like base64togallery but it’s not working
and I used file system plugin to save my image to above path

but can’t see any image on camera roll on my phone

how can I save my image to phone?

I checked below link and I think above links was right but not sure it’s still valid…