Saving an image to Camera Roll in iOS and Android



I have a really big problem that I could’t solve it for weeks. The problem is about saving an URL image (png,jpg) to local.
Now, I am using fileTransfer plugin, and I can save the image for both system.

For Android I can define a path to copy and I am creating a folder and putting inside it and requesting user to check the folder by file browser. (A dirty solution)

For iOS, when I download the URL image, it directly copy to; root:file:///var/mobile/Containers/Data/Application/blablabla/Library/Nocloud/example.png

I know, if I try to define a path for Camera Roll, iOS will not accept it.

I tried camera plugin, but it is for taking shots etc. Everything is ready, I can download the image for both systems it works, but how can I copy them to Camera Roll?

So, for both system how can I find the Camera Roll pathways? How can I copy my downloaded image to directly Camera Roll?

I would really appricate if someone can give me a solution for it…

Thank you…