Make it load only for mobiles

Hi,

I wanted to show a backtotop button only on mobiles.
I chose the easy way and set up maximum browser resolution = 667 px.
However, the icon still shows on large screen, below footer.
(screenshot of below footer: https://i.imgur.com/W3QCxFs.png )
As you can see, there’s this small arrow-up in bottom left.
How can I get rid of it ?

https://www.ads-software.com/plugins/scroll-back-to-top/