Plugin Won’t Remove

Dear developer,
I was very interested in buying your plug-in so I installed the free version to see how it would perform on my site.
Unfortunately, it turn out to be a very bad experience.
Your plug-in broke my site.
Worst I am unable to remove the code despite having removed the plug-in.

For your information, I think the issue arise from a conflict between the theme (Themeisle NEVE), OneSignal Push Notifications and your plug-in.

Despite removing your plugin and OneSignal, your code is still displaying on the page source code.

<div class=”sliding-left sliding sliding-close” id=”advanced-floating-sliding-panel-1400″ style=”left: -5px; width: 5px;”><div class=”sliding-drawer drawer-close”><div class=”sliding-knob”><p></p></div><div class=”sliding-box” style=”display: none;”></div></div><div class=”sliding-drawer drawer-close”><div class=”sliding-knob”><p></p></div><div class=”sliding-box” style=”display: none;”></div></div></div>

I would appreciate your assistance in resolving this matter.
The issue happens on every blog post of my site.
You will notice a huge Yellow Area covering the content of the page.
This happens with Mozilla, Opera on a PC and on a mobile it happens on Brave.
Prior installing your plug-in I did not had this issue.

Can you tell me which file has been modified by your plug-in so I may go and delete what is stuck there.

It would be nice to be able to use your plug-in. I would be useful for us.
Thank you in advance for addressing our challenge.

The page I need help with: [log in to see the link]