Touch Function Not working on Sunfounder 7 inch Screen

I purchased a touch screen on amazon to connect to a Raspberry Pi. The display worked but the touch function didn’t so I ordered another one because I thought it was a faulty display. However the second one didn’t work either. I tried connect it to my PC running windows 10 but it didn’t work either. am I missing something?

Which 7” touchscreen is it please? Because we sell two kinds of 7” touch screens on Amazon. A link would be great.