https://support.wix.com/en/article/corvid-creating-a-router#add-a-router
Here is the page documentation I was referring to. According to this corvid tutorial article in order to set up the router.js file as you said above you have to import from the ‘wix-router’ module. When I enter that line of code to import I get an error that the ‘wix-router’ module does not exist and as such cannot set up the routers.js file as explained how to do in the corvid article (again as linked above).