The console shows error, how to fix?

Hello
On page not working "Up" button, the console shows error, please help me understand how to correct? Copied from here, everything works here.

59da38a6cd9e0758806193.png
June 14th 19 at 18:28
1 answer
June 14th 19 at 18:30
Solution
You are not connected jQuery
Thank you, Yes. But the button still does not appear - valentine.Herman26 commented on June 14th 19 at 18:33
what button are you talking about? - Austen.Thompson53 commented on June 14th 19 at 18:36
on the button up that works there59da589b16da3618771806.png - valentine.Herman26 commented on June 14th 19 at 18:39
if you're talking about this button, it works
9OVmrkI.png

But the picture from it, you lost. - Austen.Thompson53 commented on June 14th 19 at 18:42
I substituted different pictures, even on the absolute link, for some reason does not display such style:
.scrollup {
 width: 50px;
 height: 50px;
 opacity: 0.5;
 position: fixed;
 bottom: 3.5%;
 left: 3%;
 display: none;
 text-indent: -9999px;
 background: url('../images/up.png') no-repeat fixed;
 z-index: 9;
}
- valentine.Herman26 commented on June 14th 19 at 18:45
removed fixed
9qQbq5Z.png - Austen.Thompson53 commented on June 14th 19 at 18:48

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