Service workers scripts are usually hosted at the root directory of your website, like https://yourwebsite.com/dexecure-21.js.
If you want to host the script at a different part of your website, change the Dexecure installation script to point to the correct location of your service worker script. Also note that a service worker script hosted in a subdirectory can only control pages within that subdirectory. To get around this limitation, you should set the the Service-Worker-Allowed header here.
Installing Dexecure via a Service Worker