It's really very easy on PC.
In your browser (Chrome, Firefox), simply click on the three bars/dots at the top right and open the menu.
Then go to "More tools" or "Tools"
Under Tools, open "Tools for web developers"
In the window section that opens, go to the "Network" or "Network analysis" category
If you now call up a page, you will see all the data that is loaded from this page.
If you now open an image or start a video, you will see the file that is being loaded. In Chrome, you can click on the file and right-click to save the file. Or you can open the file (image/video) in a new tab and save it from there.
Images and videos often have a cryptic name like "ah7aje725lk..."