Hey @ani.
Make sure that you've restarted Kodi after installing PreShow.
There are 2 ways to launch PreShow. The 1st is to open the context menu and select PreShow Experience.
The 2nd is to install a skin that has PreShow in it.
I don't keep track of all of the skins that work with PreShow, but here are a few that have been modified:
https://preshowexperience.com/files/category/7-skins/
Let me know if you have issues after trying these.