How does nivo slider handles uploading files

Hi everyone, firstly I am a noob and recently finished a e-commerce project with nopcommerce version 2.65. Now version 2.80 suddenly released, I really like the front-end UI of it and this Nivo slider.
I downloaded the source code version of 2.80 and took a look in Nivo slider plugin, but I have no idea how it handles the image uploads because I haven't found any codes that relates to this so far. Can anyone give me any ideas?

Faggot wrote:
In admin>configuration>plugins>nivo slider>configure you can upload images

I am talking about the source code of it and not the general configuration. I apologize if I didn't make myself clear.

Dear Faggot,

you can find it inside controller at nopCommerce->Plugin->Nop.Plugin.Widgets.NivoSlider\Controllers