This script in addition to wkof also requires WK Item Info Injector. I require it in the script. But maybe that doesn’t work for some reason. So maybe try to install it manually. (Though it worked for me without in a clean chrome install)
What Browser are you on? It works for me in Firefox, Vivaldi and Chrome
Can you click on the tampermonkey icon and confirm, that it is actually running?
During trying it out in chrome just now, I found a small issue, which I will fix now, which causes it to hang in the Loading state. But at least it shows the new section.
You could open the console (F12) and see if there is some error by WKCM2. I think I always added WKCM2 to the beginning of the logs, so you can identify it.